1,160 research outputs found

    Microcomputer based software for biodynamic simulation

    Get PDF
    This paper presents a description of a microcomputer based software package, called DYNAMAN, which has been developed to allow an analyst to simulate the dynamics of a system consisting of a number of mass segments linked by joints. One primary application is in predicting the motion of a human occupant in a vehicle under the influence of a variety of external forces, specially those generated during a crash event. Extensive use of a graphical user interface has been made to aid the user in setting up the input data for the simulation and in viewing the results from the simulation. Among its many applications, it has been successfully used in the prototype design of a moving seat that aids in occupant protection during a crash, by aircraft designers in evaluating occupant injury in airplane crashes, and by users in accident reconstruction for reconstructing the motion of the occupant and correlating the impacts with observed injuries

    Scattering of massive W bosons into gravitinos and tree unitarity in broken supergravity

    Full text link
    The WW scattering into gravitino and gaugino is here investigated in the broken phase, by using both gauge and mass eigenstates. Differently from what is obtained for unbroken gauge symmetry, we find in the scattering amplitudes new structures, which can lead to violation of unitarity above a certain scale. This happens because, in the annihilation diagram, the longitudinal degrees of freedom in the propagator of the gauge bosons disappear from the amplitude, by virtue of the SUGRA vertex. We show that the longitudinal polarizations of the on-shell W become strongly interacting in the high energy limit, and that the inclusion of diagrams with off-shell scalars of the MSSM does not cancel the divergences.Comment: 26 pages, 17 figures. Uses JHEP3.cls, epsfig.sty and axodraw.sty. Some references, together with Ward identities in the basis of mass eigenstates, have been added. Version accepted for publication in JHE

    Computational optical sensing and imaging: introduction

    Get PDF
    The OSA Topical Meeting on Computational Optical Sensing and Imaging (COSI) was held June 25–June 28, 2018 in Orlando, Florida, USA, as part of the Imaging and Applied Optics Congress. In this feature issue, we present several papers that cover the techniques, topics, and advancements in the field presented at the COSI meeting highlighting the integration of opto-electric measurement and computational processing

    A novel algorithm with IM-LSI index for incremental maintenance of materialized view

    Get PDF
    The ability to afford decision makers with both accurate and timely consolidated information as well as rapid query response times is the fundamental requirement for the success of a Data Warehouse. To provide fast access, a data warehouse stores materialized views of the sources of its data. As a result, a data warehouse needs to be maintained to keep its contents consistent with the contents of its data sources. Incremental maintenance is generally regarded as a more efficient way to maintain materialized views in a data warehouse The view has to be maintained to reflect the updates done against the base relations stored at the various distributed data sources. The proposed approach contains two modules namely, materialized view selection(MVS) and maintenance of materialized view. (MMV). In recent times, several algorithms have been proposed for keeping the views up-to-date in response to the changes in the source data. Therefore, we present an improved algorithm for MVS and MMV using IM-LSI(Itemset Mining using Latent Semantic Index) algorithm. selection of views to materialize using the IM(Itemset Mining) algorithm method to overcome the problem resulting from conventional view selection algorithms and then we consider the maintenance of materialized views using LSI. For the justification of the proposed algorithm, we reveal the experimental results in which both time and space costs better than conventional algorithms.Facultad de Informátic

    The Ionized Gas Kinematics of the LMC-Type Galaxy NGC 1427A in the Fornax Cluster

    Get PDF
    NGC 1427A is a LMC-like irregular galaxy in the Fornax cluster with an extended pattern of strong star formation around one of its edges, which is probably due to some kind of interaction with the cluster environment. We present H-alpha velocities within NGC 1427A, obtained through long-slit spectroscopy at seven different positions, chosen to fall on the brightest HII regions of the galaxy. Due to its location very near the center of the cluster this object is an excellent candidate to study the effects that the cluster environment has on gas-rich galaxies embedded in it. The rotation of NGC 1427A is modeled in two different ways. The global ionized gas kinematics is reasonably well described by solid-body rotation, although on small scales it shows a chaotic behaviour. In this simple model, the collision with a smaller member of the cluster as being responsible for the peculiar morphology of NGC 1427A is very unlikely, since the only candidate intruder falls smoothly into the general velocity pattern of the main galaxy. In a more elaborate model, for which we obtain a better solution, this object does not lie in the same plane of NGC 1427A, in which case we identify it as a satellite bound to the galaxy. These results are discussed in the context of a normal irregular versus one interacting with some external agent. Based on several arguments and quantitative estimates, we argue that the passage through the hot intracluster gas of the Fornax cluster is a very likely scenario to explain the morphological properties of NGC 1427A.Comment: 31 pages, LaTeX2e, uses aas2pp4.sty and psfig.sty, including 7 Postscript figures; accepted for publication in ApJ, Vol. 530, February 200

    Scaling and Memory Effect in Volatility Return Interval of the Chinese Stock Market

    Full text link
    We investigate the probability distribution of the volatility return intervals τ\tau for the Chinese stock market. We rescale both the probability distribution Pq(τ)P_{q}(\tau) and the volatility return intervals τ\tau as Pq(τ)=1/τˉf(τ/τˉ)P_{q}(\tau)=1/\bar{\tau} f(\tau/\bar{\tau}) to obtain a uniform scaling curve for different threshold value qq. The scaling curve can be well fitted by the stretched exponential function f(x)∼e−αxγf(x) \sim e^{-\alpha x^{\gamma}}, which suggests memory exists in τ\tau. To demonstrate the memory effect, we investigate the conditional probability distribution Pq(τ∣τ0)P_{q} (\tau|\tau_{0}), the mean conditional interval and the cumulative probability distribution of the cluster size of τ\tau. The results show clear clustering effect. We further investigate the persistence probability distribution P±(t)P_{\pm}(t) and find that P−(t)P_{-}(t) decays by a power law with the exponent far different from the value 0.5 for the random walk, which further confirms long memory exists in τ\tau. The scaling and long memory effect of τ\tau for the Chinese stock market are similar to those obtained from the United States and the Japanese financial markets.Comment: 10 elsart pages including 7 eps figure

    The cool wake around 4C 34.16 as seen by XMM-Newton

    Full text link
    We present XMM-Newton observations of the wake-radiogalaxy system 4C34.16, which shows a cool and dense wake trailing behind 4C34.16's host galaxy. A comparison with numerical simulations is enlightening, as they demonstrate that the wake is produced mainly by ram pressure stripping during the galactic motion though the surrounding cluster. The mass of the wake is a substantial fraction of the mass of an elliptical galaxy's X-ray halo. This observational fact supports a wake formation scenario similar to the one demonstrated numerically by Acreman et al (2003): the host galaxy of 4C34.16 has fallen into its cluster, and is currently crossing its central regions. A substantial fraction of its X-ray halo has been stripped by ram pressure, and remains behind to form the galaxy wake.Comment: 9 pages, 6 figures, accepted for publication in MNRA
    • …
    corecore