| 541. |
- Hanson, Lars, et al.
(författare)
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Guide and documentation system to support digital human modeling applications
- 2006
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Ingår i: International Journal of Industrial Ergonomics. - : Elsevier BV. - 0169-8141 .- 1872-8219. ; 36:1, s. 17-24
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Tidskriftsartikel (refereegranskat)abstract
- Car developers use digital human modeling tools to analyze and visualize car interiors in relation to human characteristics before the vehicles are actually constructed. Developers, reviewers and users of human simulation tools often claim that such tools can reduce development time and costs. In car industry companies today, human simulation tools are used by a single or a few experts in an informal working process with insufficient documentation. To prepare for extensive, effective and efficient use of human simulation modeling tools in industry with several users within a company, the aim of this study was to design and evaluate a digital guide and documentation system to support digital human modeling applications. A participative design approach was used in developing the guide, involving human simulation tool users and managers within the General Motors Group. The system consists of two major parts: a usage guide and database. The usage guide is divided into three sections considering the professionals involved: (1) initiation of human vehicle interaction analysis, (2) preparation and running of the digital human tool and (3) recommendation formulation and closure. The guide was connected to a database with search and print capabilities for previous and ongoing human simulation analyses. Sixteen subjects from industry and university settings evaluated the support system. Results showed that the users appreciated the guide and documentation system, in particular, the database for storing human simulation work. The guide was perceived as being especially useful for guidance in large analyses, whereas for smaller ones the subjects felt the formalized guide was too lengthy and time consuming. The use of the formalized guide is likely to reduce differences in results, within and between tool users. The support system guides the simulation tool user through an acknowledged process; it documents, stores and keeps track of ongoing and previous analyses, and facilitates the reuse of studies. Relevance to industry The system can be very helpful for industries striving to improve process quality and documentation of digital human modeling analyses. (c) 2005 Elsevier B.V. All rights reserved.
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| 542. |
- Harre, J. V., et al.
(författare)
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Examining the orbital decay targets KELT-9 b, KELT-16 b, and WASP-4 b, and the transit-timing variations of HD 97658 b
- 2023
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 669
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Tidskriftsartikel (refereegranskat)abstract
- Context. Tidal orbital decay is suspected to occur for hot Jupiters in particular, with the only observationally confirmed case of this being WASP-12 b. By examining this effect, information on the properties of the host star can be obtained using the so-called stellar modified tidal quality factor Q′∗, which describes the efficiency with which the kinetic energy of the planet is dissipated within the star. This can provide information about the interior of the star. Aims. In this study, we aim to improve constraints on the tidal decay of the KELT-9, KELT-16, and WASP-4 systems in order to find evidence for or against the presence of tidal orbital decay. With this, we want to constrain the Q′∗ value for each star. In addition, we aim to test the existence of the transit timing variations (TTVs) in the HD 97658 system, which previously favoured a quadratic trend with increasing orbital period. Methods. Making use of newly acquired photometric observations from CHEOPS (CHaracterising ExOplanet Satellite) and TESS (Transiting Exoplanet Survey Satellite), combined with archival transit and occultation data, we use Markov chain Monte Carlo (MCMC) algorithms to fit three models to the data, namely a constant-period model, an orbital-decay model, and an apsidal-precession model. Results. We find that the KELT-9 system is best described by an apsidal-precession model for now, with an orbital decay trend at over 2 σ being a possible solution as well. A Keplerian orbit model with a constant orbital period provides the best fit to the transit timings of KELT-16 b because of the scatter and scale of their error bars. The WASP-4 system is best represented by an orbital decay model at a 5 σ significance, although apsidal precession cannot be ruled out with the present data. For HD 97658 b, using recently acquired transit observations, we find no conclusive evidence for a previously suspected strong quadratic trend in the data.
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| 543. |
- Hartwig, Jonas T., 1980, et al.
(författare)
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Deformations of Lie Algebras using σ-Derivations
- 2006
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Ingår i: Journal of Algebra. - : Elsevier BV. - 0021-8693. ; 295:2, s. 314-361
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Tidskriftsartikel (refereegranskat)abstract
- In this article we develop an approach to deformations of the Witt and Virasoro algebras based on sigma-derivations. We show that sigma-twisted Jacobi type identity holds for generators of such deformations. For the sigma-twisted generalization of Lie algebras modeled by this construction, we develop a theory of central extensions. We show that our approach can be used to construct new deformations of Lie algebras and their central extensions, which in particular include naturally the q-deformations of the Witt and Virasoro algebras associated to q-difference operators, providing also corresponding q-deformed Jacobi identities. (c) 2005 Elsevier Inc. All rights reserved.
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| 544. |
- Harvey, N. C., et al.
(författare)
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FRAX predicts incident falls in elderly men : findings from MrOs Sweden
- 2016
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Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 27:1, s. 267-274
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Tidskriftsartikel (refereegranskat)abstract
- A Summary Falls and fractures share several common risk factors. Although past falls is not included as an input variable in the FRAX calculator, we demonstrate that FRAX probability predicts risk of incident falls in the MrOs Sweden cohort. Introduction Although not included in the FRAXA (R) algorithm, it is possible that increased falls risk is partly dependent on other risk factors that are incorporated into FRAX. The aim of the present study was to determine whether fracture probability generated by FRAX might also predict risk of incident falls and the extent that a falls history would add value to FRAX. Methods We studied the relationship between FRAX probabilities and risk of falls in 1836 elderly men recruited to the MrOS study, a population-based prospective cohort of men from Sweden. Baseline data included falls history, clinical risk factors, bone mineral density (BMD) at femoral neck, and calculated FRAX probabilities. Incident falls were captured during an average of 1.8 years of follow-up. An extension of Poisson regression was used to investigate the relationship between FRAX, other risk variables, and the time-to-event hazard function of falls. All associations were adjusted for age and time since baseline. Results At enrolment, 15.5 % of the men had fallen during the preceding 12 months (past falls) and 39 % experienced one or more falls during follow-up (incident falls). The risk of incident falls increased with increasing FRAX probabilities at baseline (hazard ratio (HR) per standard deviation (SD), 1.16; 95 % confidence interval (95%CI), 1.06 to 1.26). The association between incident falls and FRAX probability remained after adjustment for past falls (HR per SD, 1.12; 95%CI, 1.03 to 1.22). High compared with low baseline FRAX score (>15 vs <15 % probability of major osteoporotic fracture) was strongly predictive of increased falls risk (HR, 1.64; 95%CI, 1.36 to 1.97) and remained stable with time. Whereas past falls were a significant predictor of incident falls (HR, 2.75; 95%CI, 2.32 to 3.25), even after adjustment for FRAX, the hazard ratio decreased markedly with increasing follow-up time. Conclusions Although falls are not included as an input variable, FRAX captures a component of risk for future falls and outperforms falls history with an extended follow-up time.
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| 545. |
- Hawthorn, F., et al.
(författare)
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TOI-836: A super-Earth and mini-Neptune transiting a nearby K-dwarf
- 2023
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Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 520:3, s. 3649-3668
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Tidskriftsartikel (refereegranskat)abstract
- We present the discovery of two exoplanets transiting TOI-836 (TIC 440887364) using data from TESS Sector 11 and Sector 38. TOI-836 is a bright (T = 8.5 mag), high proper motion (∼200 mas yr−1), low metallicity ([Fe/H]≈−0.28) K-dwarf with a mass of 0.68 ± 0.05 M and a radius of 0.67 ± 0.01 R. We obtain photometric follow-up observations with a variety of facilities, and we use these data sets to determine that the inner planet, TOI-836 b, is a 1.70 ± 0.07 R super-Earth in a 3.82-d orbit, placing it directly within the so-called ‘radius valley’. The outer planet, TOI-836 c, is a 2.59 ± 0.09 R mini-Neptune in an 8.60-d orbit. Radial velocity measurements reveal that TOI-836 b has a mass of 4.5 ± 0.9 M, while TOI-836 c has a mass of 9.6 ± 2.6 M. Photometric observations show Transit Timing Variations (TTVs) on the order of 20 min for TOI-836 c, although there are no detectable TTVs for TOI-836 b. The TTVs of planet TOI-836 c may be caused by an undetected exterior planet.
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| 546. |
- He, Bin, et al.
(författare)
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Worldwide impacts of atmospheric vapor pressure deficit on the interannual variability of terrestrial carbon sinks
- 2022
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Ingår i: National Science Review. - : Oxford University Press (OUP). - 2095-5138 .- 2053-714X. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- Interannual variability of the terrestrial ecosystem carbon sink is substantially regulated by various environmental variables and highly dominates the interannual variation of atmospheric carbon dioxide (CO2) concentrations. Thus, it is necessary to determine dominating factors affecting the interannual variability of the carbon sink to improve our capability of predicting future terrestrial carbon sinks. Using global datasets derived from machine-learning methods and process-based ecosystem models, this study reveals that the interannual variability of the atmospheric vapor pressure deficit (VPD) was significantly negatively correlated with net ecosystem production (NEP) and substantially impacted the interannual variability of the atmospheric CO2 growth rate (CGR). Further analyses found widespread constraints of VPD interannual variability on terrestrial gross primary production (GPP), causing VPD to impact NEP and CGR. Partial correlation analysis confirms the persistent and widespread impacts of VPD on terrestrial carbon sinks compared to other environmental variables. Current Earth system models underestimate the interannual variability in VPD and its impacts on GPP and NEP. Our results highlight the importance of VPD for terrestrial carbon sinks in assessing ecosystems' responses to future climate conditions.
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| 547. |
- He, Wenxiao, 1985, et al.
(författare)
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Formation of Bone-like Nanocrystalline Apatite Using Self-Assembled Liquid Crystals
- 2012
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 24:5, s. 892-902
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Tidskriftsartikel (refereegranskat)abstract
- A two-step process using liquid crystalline phases combined with controlled postcrystallization for the preparation of bone-like apatite has been developed. First, amorphous calcium phosphate (ACP) spherules with a diameter of 10.8 +/- 1.4 nm and specific surface area (SSA) in the range of 150-170 m(2)/g were synthesized within a reverse hexagonal liquid crystalline (LC) phase. Second, the ACP spherules were dispersed and aged in Milli-Qwater, where they crystallized into poorly crystalline apatite (PCA). The addition of heparin during aging was explored, which was shown to retard the ACP - PCA conversion. The particle formation within the LC phase was monitored using synchrotron small-angle X-ray scattering, and the formed materials were characterized by X-ray diffraction, conventional and high-resolution transmission electron microscopy, nitrogen adsorption, thermogravimetry with infrared-coupled analysis, and Raman spectroscopy. The PCA formed using the LC aging route presented bone-resembling features, such as,Ca2+ and OH- deficiency, CO32- substitution, poor crystallinity; and ultrahigh SSA of 356 m(2)/g. The resulting particles were compared to hydroxyapatite synthesized via a conventional water-based precipitation method. The LC-aging route exhibited excellent controllability over the CaP crystallization, which enabled facile tailoring of the resulting material properties for different types of application.
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| 548. |
- Hearn, William, 1992, et al.
(författare)
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In situ tempering of martensite during laser powder bed fusion of Fe-0.45C steel
- 2022
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Ingår i: Materialia. - : Elsevier BV. - 2589-1529. ; 23
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Tidskriftsartikel (refereegranskat)abstract
- During laser powder bed fusion (L-PBF), materials experience cyclic re-heating as new layers are deposited, inducing an in situ tempering effect. In this study, the effect of this phenomenon on the tempering of martensite during L-PBF was examined for Fe-0.45C steel. Detailed scanning electron microscopy, transmission electron microscopy, atom probe tomography, and hardness measurements indicated that martensite was initially in a quenched-like state after layer solidification, with carbon atoms segregating to dislocations and to martensite lath boundaries. Subsequent tempering of this quenched-like martensite was the result of two in situ phenomena: (i) micro-tempering within the heat affected zone and (ii) macro-tempering due to heat conduction and subsequent heat accumulation. Hardness measurements showed that although both influenced martensite tempering, micro-tempering had the most significant effect, as it reduced martensite hardness by up to ∼380 HV. This reduction was due to the precipitation of nano-sized Fe3C carbides at the previously carbon-enriched boundaries. Lastly, the magnitude of in situ tempering was found to be related to the energy input, where increasing the volumetric energy density from 60 to 190 J/mm3 reduced martensite hardness by ∼100 HV. These findings outline the stages of martensite tempering during L-PBF and indicate that the level of tempering can be adjusted by tailoring the processing parameters.
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| 549. |
- Hedberg Wallenstein, Joachim, 1986, et al.
(författare)
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Chemical consequences of pyrazole orientation in RuII complexes of unsymmetric quinoline-pyrazole ligands
- 2016
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 45:29, s. 11723-11732
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Tidskriftsartikel (refereegranskat)abstract
- A series of homoleptic RuII complexes including the tris-bidentate complexes of a new bidentate ligand 8-(1-pyrazol)-quinoline (Q1Pz) and bidentate 8-(3-pyrazol)-quinoline (Q3PzH), as well as the bis-tridentate complex of bis(quinolinyl)-1,3-pyrazole (DQPz) was studied. Together these complexes explore the orientation of the pyrazole relative to the quinoline. By examining the complexes structurally, photophysically, photochemically, electrochemically, and computationally by DFT and TD-DFT, it is shown that the pyrazole orientation has a significant influence on key properties. In particular, its orientation has noticeable effects on oxidation and reduction potentials, photostability and proton sensitivity, indicating that [Ru(Q3PzH)3]2+ is a particularly good local environment acidity-probe candidate.
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| 550. |
- Hedell, Ronny, 1985, et al.
(författare)
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Determining the optimal forensic DNA analysis procedure following investigation of sample quality
- 2018
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Ingår i: International Journal of Legal Medicine. - : Springer Science and Business Media LLC. - 0937-9827 .- 1437-1596. ; 132:4, s. 955-966
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 Springer-Verlag GmbH Germany Crime scene traces of various types are routinely sent to forensic laboratories for analysis, generally with the aim of addressing questions about the source of the trace. The laboratory may choose to analyse the samples in different ways depending on the type and quality of the sample, the importance of the case and the cost and performance of the available analysis methods. Theoretically well-founded guidelines for the choice of analysis method are, however, lacking in most situations. In this paper, it is shown how such guidelines can be created using Bayesian decision theory. The theory is applied to forensic DNA analysis, showing how the information from the initial qPCR analysis can be utilized. It is assumed the alternatives for analysis are using a standard short tandem repeat (STR) DNA analysis assay, using the standard assay and a complementary assay, or the analysis may be cancelled following quantification. The decision is based on information about the DNA amount and level of DNA degradation of the forensic sample, as well as case circumstances and the cost for analysis. Semi-continuous electropherogram models are used for simulation of DNA profiles and for computation of likelihood ratios. It is shown how tables and graphs, prepared beforehand, can be used to quickly find the optimal decision in forensic casework.
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