| 11. |
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| 12. |
- Wanner, Bertil, 1963-, et al.
(författare)
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Cutter Exit Effects during Milling of Thin-walled Inconel 718
- 2012
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Ingår i: Advanced Materials Research. - : Trans Tech Publications Inc.. - 1022-6680 .- 1662-8985. ; 590, s. 297-308, s. 297-308
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Tidskriftsartikel (refereegranskat)abstract
- During milling of thin-walled components, chatter vibrations give rise to process issues. These include dimensional inaccuracy, damaged and scrap parts, and damaged cutting tools. This, in turn, leads to loss of production time with increasing cost as a consequence. This paper identifies the force profile during a single cut milling process. It focuses on the exit and post-exit behavior of the cut and discusses the process dynamics. The force profiles of various tool-to-workpiece positions are analyzed as regards the exit and post exit phases. A standard on-the-market cutter and a specially designed zero rake cutter are used in the investigation. Finally, a time-domain simulation of the force is performed and compared to the experimental results. The study concludes that a small change in exit angle may result in a considerable improvement in cutting behavior. In addition, the tool position should be chosen so that the cutter exits in the least flexible direction possible for the workpiece.
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| 13. |
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| 14. |
- Katselis, Dimitrios, et al.
(författare)
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OOK/DS-CDMA bit error probability over Rayleigh fading channels
- 2013
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Ingår i: Communications (ICC), 2013 IEEE International Conference on. - : IEEE conference proceedings. - 9781467331227 ; , s. 5619-5624
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Konferensbidrag (refereegranskat)abstract
- A major constraint in deployments of resource-limited networks is the energy consumption related to the battery lifetime of the network nodes. To this end, power efficient digital modulation techniques such as On-Off keying (OOK) are highly attractive. In this paper, a novel complete probabilistic description of the Direct Sequence - Coded Division Multiple Access (DS-CDMA) system with random signatures employing OOK modulation is presented. The system scenario considers simultaneously transmitting nodes in Rayleigh fading conditions. Numerical simulations are provided to support the derived results.
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| 15. |
- Colangelo, Gilberto, et al.
(författare)
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Finite volume effects for nucleon and heavy meson masses
- 2010
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Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 82:3
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Tidskriftsartikel (refereegranskat)abstract
- We apply the resummed version of the Luscher formula to analyze finite volume corrections to the mass of the nucleon and of heavy mesons. We show that by applying the subthreshold expansion of the scattering amplitudes one can express the finite volume corrections in terms of only a few physical observables and the size of the box. In the case of the nucleon, the available information about the quark mass dependence of these physical quantities is discussed and used to assess the finite volume corrections to the nucleon mass as a function of the quark mass including a detailed analysis of the remaining uncertainties. For heavy mesons, the Luscher formula is derived both fully relativistically and in a nonrelativistic approximation and a first attempt at a numerical analysis is made.
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| 16. |
- Zou, F, et al.
(författare)
-
A novel statistical approach for jointly analyzing RNA-Seq data from F1 reciprocal crosses and inbred lines
- 2014
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Ingår i: Genetics. - : Oxford University Press (OUP). - 1943-2631. ; 197:1, s. 389-399
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Tidskriftsartikel (refereegranskat)abstract
- RNA sequencing (RNA-seq) not only measures total gene expression but may also measure allele-specific gene expression in diploid individuals. RNA-seq data collected from F1 reciprocal crosses in mice can powerfully dissect strain and parent-of-origin effects on allelic imbalance of gene expression. In this article, we develop a novel statistical approach to analyze RNA-seq data from F1 and inbred strains. Method development was motivated by a study of F1 reciprocal crosses derived from highly divergent mouse strains, to which we apply the proposed method. Our method jointly models the total number of reads and the number of allele-specific reads of each gene, which significantly boosts power for detecting strain and particularly parent-of-origin effects. The method deals with the overdispersion problem commonly observed in read counts and can flexibly adjust for the effects of covariates such as sex and read depth. The X chromosome in mouse presents particular challenges. As in other mammals, X chromosome inactivation silences one of the two X chromosomes in each female cell, although the choice of which chromosome to be silenced can be highly skewed by alleles at the X-linked X-controlling element (Xce) and stochastic effects. Our model accounts for these chromosome-wide effects on an individual level, allowing proper analysis of chromosome X expression. Furthermore, we propose a genomic control procedure to properly control type I error for RNA-seq studies. A number of these methodological improvements can also be applied to RNA-seq data from other species as well as other types of next-generation sequencing data sets. Finally, we show through simulations that increasing the number of samples is more beneficial than increasing the library size for mapping both the strain and parent-of-origin effects. Unless sample recruiting is too expensive to conduct, we recommend sequencing more samples with lower coverage.
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| 17. |
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| 18. |
- Gallas, B., et al.
(författare)
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Changes in optical properties of MnAs thin films on GaAs(001) induced by a- to B-phase transition
- 2008
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Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley-VCH Verlagsgesellschaft. - 1862-6300 .- 1862-6319. ; 205:4, s. 859-862
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Tidskriftsartikel (refereegranskat)abstract
- MnAs layers with 45 nm thickness were grown epitaxially on GaAs(001) substrates. Ellipsometry measurements were made in the spectral range 0.045 eV to 6 eV as a function of temperature (between –10 °C and 50 °C) at 70° of incidence. In this way the transition from the hexagonal α-phase to the orthorhombic β-phase could be monitored. Non-zero off-diagonal elements of the Jones matrix for an azimuth of 38° off the [10] axis of the substrate indicate that the optical functions of MnAs are anisotropic in both phases. The optical conductivity exhibits low-energy interband transitions around 0.3 eV, more clearly seen in the α-phase than in the β-phase. Extrapolation of the optical conductivity to zero frequency confirms that the α-phase is about two times more conducting than the β-phase. A broad structure is observed in the visible range around 3 eV. The α-phase is characterised by an anisotropy induced energy difference of this structure with a maximum at 2.8 eV for the extraordinary index and at 3.15 eV for the ordinary index. This difference vanishes in the β-phase in which anisotropy mainly induces changes in amplitude of the 3 eV structure. The assignment of the structures will be discussed.
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| 19. |
- Makko, Aryo, 1979-
(författare)
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Realistisk idealism : ESK-processen, Olof Palme och kalla kriget
- 2012
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Ingår i: Kalla kriget. - Stockholm : Axel och Margaret Ax:son Johnsons stiftelse för allmännyttiga ändamål. - 9789189672451 ; , s. 227-235
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Bokkapitel (populärvet., debatt m.m.)abstract
- Den etablerade forskningen kring svensk utrikespolitik använder sig av beteckningen ”Palmes världssamvete” för att kontrastera övergången från Östen Undéns passiva linje till 1960 och 1970-talens aktiva utrikespolitik. Under ESK-processen agerade Sverige varken aktivt eller solidariskt utan bedrev klassisk realpolitik med stark fokus på nedrustning. De östeuropeiska folkens rättigheter och öde spelade en underordnad roll vilket väcker nya frågor kring den aktiva utrikespolitikens natur och motivering.
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| 20. |
- Wresnik, Jörg, et al.
(författare)
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Modeling thermal deformation of VLBI antennas with a new temperature model
- 2007
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Ingår i: Journal of Geodesy. - : Springer Science and Business Media LLC. - 0949-7714 .- 1432-1394. ; 81:6-8, s. 433-441
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Tidskriftsartikel (refereegranskat)abstract
- Temperature variations at very long baseline interferometry (VLBI) sites cause thermal deformations of the VLBI antennas and corresponding displacements of the VLBI reference points. The thermal deformation effects typically contain seasonal and daily signatures. The amplitudes of the annual vertical motion of the antenna reference point can reach several millimeters, depending on the design of the antenna structure, on the material, and on the environmental effects such as global station position, station height and climatology effects. Simple methods to correct this effect use the difference of the environmental temperature with respect to a defined reference temperature, the antenna dimensions, the elevation of the antenna, the material of antenna structure. Applying these simple models for thermal deformation in the VLBI data analysis improves the baseline length repeatability by 3.5%. A comparison of these simple models with local thermal deformation measurements at the antennas in Onsala and Wettzell show that the local measurements and the modeled corrections agree well when the temperature of the antenna structure is used, but agree less good when the surrounding air temperatures are used. To overcome this problem we present a method to model temperature penetration into the antenna structures, that allows to model thermal deformation effects that agree with the observed vertical deformation of the Onsala and Wettzell radio telescopes with a root mean square deviation of 0.07 and 0.13 mm, respectively. Possible implementations in the VLBI analysis are presented, and the definition of an adequate reference temperature is discussed. © Springer-Verlag 2006.
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