1,589 research outputs found

    Connecting Abaqus and CATIA V5 in product development

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    Abstract. In this work Abaqus software, which is used for doing finite element analysis, and the associative interface of CATIA V5 computer-aided design software and Abaqus were researched. From the associative interface, the usage with Abaqus and the usage’s requirements were researched. From Abaqus it’s usage and requirements were studied. The software was also explored by a case study. In the case study there was no need to utilize the associativity of the associative interface. The methods of research in this work were computer-aided design, finite element analysis and the connection of those through associative interface. In this work it was clarified how the associative interface works with Abaqus by the features, and how Abaqus works by its modules. This work included a case study, in which squeezing of a cavity seal between two plastic shells was simulated. In the case study nonlinear material model for the cavity seal was used. The case study was challenging due high nonlinearity and included especially calculation time challenges. In the case study a situation occurred where the simulation did not pass every step. Because of that a decision was made to make a second finite element analysis model, where the cavity seal model was replaced by gasket model that was simpler in terms of the calculations. The old model was named as model A and the new model as model B. In case study’s results models A and B were compared, and represented shell’s strains and stress of screw towers were calculated by model B. In the work’s discussion the benefits of associative interface with Abaqus were discussed together with an export problem which appeared during the work, a need of expert for making simulations and the change of gasket model in the case study. As conclusions it was stated of the associative interface that its very useful with Abaqus, and it does not need special skills or experience for the use. However, as a conclusion it was stated that training is needed for use of Abaqus.Abaqus ja CATIA V5 -ohjelmistojen yhdistäminen tuotekehityksessä. Tiivistelmä. Tässä työssä tutkittiin Dassault Systémesin Abaqus-ohjelmaa, jolla tehdään elementtianalyyseja sekä CATIA V5 -tietokoneavusteisen suunnitteluohjelman ja Abaquksen välistä assosiatiivista käyttöliittymää. Assosiatiivisesta käyttöliittymästä tutkittiin yhteiskäyttöä Abaquksen kanssa, ja yhteiskäytön vaatimuksia. Abaquksesta tutkittiin käyttöä ja käytön vaatimuksia. Ohjelmistoon tutustuttiin myös esimerkkitapauksen avulla. Tässä esimerkkitapauksessa ei tarvinnut hyödyntää assosiatiivisen käyttöliittymän assosiatiivisuutta. Käytettävät tutkimusmenetelmät työssä olivat tietokoneavusteinen suunnittelu, elementtianalyysi, ja tietokoneavusteisen suunnittelun ja elementtianalyysin yhdistäminen. Työssä selvitettiin, miten assosiatiivinen käyttöliittymä toimii Abaquksen kanssa ominaisuuksittain ja miten Abaqus toimii moduuleittain. Lisäksi työ sisälsi esimerkkitapauksen, jossa simuloitiin ontelotiivisteen puristusta kahden muovikuoren väliin. Esimerkkitapauksessa käytettiin epälineaarista materiaalimallia ontelotiivisteelle. Tämä esimerkkitapaus oli vaativa ja sisälsi erityisesti laskenta-aikahaasteita. Esimerkkitapauksessa päädyttiin tilanteeseen, jossa simulaatio ei mennyt kaikkein vaiheiden läpi. Tämän takia päädyttiin tekemään toinenkin elementtianalyysimalli, jossa ontelotiivistemalli oli korvattu laskennan kannalta yksinkertaisemmalla tiivistemallilla. Vanha malli nimettiin malli A:ksi, ja uusi malli nimettiin malli B:ksi. Esimerkkitapauksen tuloksissa vertailtiin malleja A ja B, ja otettiin esiin mallilla B laskettuja kuorten venymiä ja ruuvitornien jännitystiloja. Työn käsittelyosuudessa käsiteltiin assosiatiivisen käyttöliittymän hyötyjä Abaquksen kanssa, työtä tehdessä ilmenneeseen tiedonvienti ongelmaan, asiantuntijan tarvetta esimerkkitapauksen simulaatiota tehdessä ja tiivistemallin vaihtoa työssä. Johtopäätöksinä assosiatiivisesta käyttöliittymästä todettiin, että se on Abaquksen kanssa hyvin käyttökelpoinen, eikä tarvitse erikoisosaamista tai -kokemusta käyttöä varten. Johtopäätöksenä Abaquksesta todettiin, että se tarvitsee käyttöä varten kouluttautumista

    Towards machines that understand people

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    The ability to estimate the state of a human partner is an insufficient basis on which to build cooperative agents. Also needed is an ability to predict how people adapt their behavior in response to an agent's actions. We propose a new approach based on computational rationality, which models humans based on the idea that predictions can be derived by calculating policies that are approximately optimal given human‐like bounds. Computational rationality brings together reinforcement learning and cognitive modeling in pursuit of this goal, facilitating machine understanding of humans

    Aqueous and non-aqueous microchip electrophoresis with on-chip electrospray ionization mass spectrometry on replica-molded thiol-ene microfluidic devices

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    This work describes aqueous and non-aqueous capillary electrophoresis on thiol-ene-based microfluidic separation devices that feature fully integrated and sharp electrospray ionization (ESI) emitters. The chip fabrication is based on simple and low-cost replica-molding of thiol-ene polymers under standard laboratory conditions. The mechanical rigidity and the stability of the materials against organic solvents, acids and bases could be tuned by adjusting the respective stoichiometric ratio of the thiol and allyl ("ene") monomers, which allowed us to carry out electrophoresis separation in both aqueous and non-aqueous (methanol- and ethanol-based) background electrolytes. The stability of the ESI signal was generallyPeer reviewe

    Laser Spectroscopy of Niobium Fission Fragments: First Use of Optical Pumping in an Ion Beam Cooler Buncher

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    A new method of optical pumping in an ion beam cooler buncher has been developed to selectively enhance ionic metastable state populations. The technique permits the study of elements previously inaccessible to laser spectroscopy and has been applied here to the study of Nb. Model independent mean-square charge radii and nuclear moments have been studied for 90,90m,91,91m,92,93,99,101,103^{90,90 m,91,91 m,92,93,99,101,103}Nb to cover the region of the N=50 shell closure and N≈60 sudden onset of deformation. The increase in mean-square charge radius is observed to be less than that for Y, with a substantial degree of β softness observed before and after N=60

    Citizen Attitudes to Farm Animals in Finland – A Population-Based Study

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    Citizen attitudes and opinions form an important driving force for improvements in the ethical status of farm animals in society. Hence, it is important to understand how attitudes to farm animals vary in society and what factors, mechanisms and social processes influence the development of these attitudes. In this study we examine the relative importance of socio-demographic background, animal related experiences and social-equality attitudes in the formation of attitudes to farm animals in Finland. The research is based on a nationwide survey (n = 1890). Our research findings suggest that female gender, young age, urban residency, a non-farming background and social-equality attitudes are linked to greater concern for farm animals. A farming background, valuing social equality, and gender have the strongest connections to farm animal attitudes, followed by age and place of residence. Having a companion animal and education level have a relatively modest connection to attitudes to farm animals. In order to accumulate comparative evidence of social-group differences in attitudes to farm animals, further research should continue to develop improved indicators for attitudes to farm animal welfare and rights. Moreover, explanations for social-group differences in citizen attitudes to farm animals should be subjected to further empirical testing.</p

    Variation in the physical properties of oat groats, flakes and oat flake flour - Processability of thirty pure cultivar oat batches from Finland

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    The aim of this study was to understand the processability of thirty pure cultivar oat batches and how the physical properties of oat groats and flakes affect the characteristics of oat flake flour. This was conducted by investigating the relationship between the chemical composition of oats and the physical characteristics of oat groats, flakes and flours produced by industrial scale milling process. It was clearly shown that the oat batches behaved differently in the milling process and that the physical characteristics of oat groats, flakes and flours were interrelated. For example, separation of bran and endosperm particles of oat flours by dry fractionation was connected to the chemical composition as well as particle size distribution of the flours. Furthermore, it was shown that flowability properties of oat flours affect the bran-endosperm separation of oat flour by dry fractionation. This study demonstrated the role of the oat raw material in the milling process as well as the relationship between the different mill products, which deepens the understanding of oat milling process and is important when aiming at producing oat products with high quality.Peer reviewe

    Baryogenesis with Superheavy Squarks

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    We consider a setup where R-parity is violated in the framework of split supersymmetry. The out-of-equilibrium decays of heavy squarks successfully lead to the generation of a baryon asymmetry. We restrict the R-parity violating couplings to the baryon number violating subset to keep the neutralino sufficiently stable to provide the dark matter. The observed baryon asymmetry can be generated for squark masses larger than 10^11 GeV, while neutralino dark matter induces a stronger bound of 10^13 GeV. Some mass splitting between left- and right-handed squarks may be needed to satisfy also constraints from gluino cosmology.Comment: 18 pages, LaTeX, 4 figure

    Non-Gaussianity from Instant and Tachyonic Preheating

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    We study non-Gaussianity in two distinct models of preheating: instant and tachyonic. In instant preheating non-Gaussianity is sourced by the local terms generated through the coupled perturbations of the two scalar fields. We find that the non-Gaussianity parameter is given by fNLϕ2g<O(1)f_{NL}^{\phi}\sim 2g < O(1), where gg is a coupling constant, so that instant preheating is unlikely to be constrained by WMAP or Planck. In the case of tachyonic preheating non-Gaussianity arises solely from the instability of the tachyon matter and is found to be large. We find that for single field inflation the present WMAP data implies a bound V01/4/MP104V_{0}^{1/4}/M_{P}\leq 10^{-4} on the scale of tachyonic instability. We argue that the tachyonic preheating limits are useful also for string-motivated inflationary models.Comment: 12 pages, 1 figure, additional discussion, improved constraint on the scale of tachyonic preheatin

    Mapping the proton drip line from Z=31 to Z=49

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    The structure of proton drip line nuclei in the 60 < A < 100 mass range is studied with the Relativistic Hartree Bogoliubov (RHB) model. For the elements which determine the astrophysical rapid proton capture process path, the RHB model predicts the location of the proton drip-line, the ground-state quadrupole deformations and one-proton separation energies at and beyond the drip-line. The results of the present theoretical investigation are compared with available experimental data. For possible odd-Z ground state proton emitters, the calculated deformed single-particle orbitals occupied by the odd valence proton and the corresponding spectroscopic factors are compared with predictions of the macroscopic-microscopic mass model.Comment: 20 pages, LaTeX, 6 eps figs, submitted to Nucl. Phys.

    Assessing, treating and preventing community acquired pneumonia in older adults: findings from a community-wide survey of emergency room and family physicians

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    BACKGROUND: Respiratory infections, like pneumonia, represent an important threat to the health of older Canadians. Our objective was to determine, at a community level, family and emergency room physicians' knowledge and beliefs about community acquired pneumonia (CAP) in older adults and to describe their self-reported assessment, management and prevention strategies. METHODS: All active ER and family physicians in Brant County received a mailed questionnaire. An advance notification letter and three follow-up mailings were used to maximize physician participation rate. The questionnaire collected information about physicians' assessment, management, and prevention strategies for CAP in older adults (≥60 years of age) plus demographic, training, and practice characteristics. The analysis highlights differences in approaches between office-based and emergency department physicians. RESULTS: Seventy-seven percent of physicians completed and returned the survey. Although only 16% of physicians were very confident in assessing CAP in older adults, more than half reported CAP to be a very important health concern in their practices. In-service training for family physicians was associated with increased confidence in CAP assessment and more frequent use of diagnostic tests. Family physicians who reported always requesting chest x-rays were also more likely to request pulse oximetry (OR 5.6, 95% CI 1.40 to 22.5) and recommend both follow-up x-rays (OR 5.4, 95% CI 1.7 to 16.6) and pneumococcal vaccination (OR 3.4, 95% CI 1.1 to 10.0). CONCLUSION: The findings of this study provide a snapshot of how non-specialists from a non-urban Ontario community assess, manage and prevent CAP in older adults and highlight differences between office-based and emergency department physicians. This information can guide researchers and clinicians in their efforts to improve the management and prevention of CAP in older adults
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