900 research outputs found

    DETERMINANTS ANALYSIS OF GROWTH RATE IN PRIVATE EQUITY MARKET

    Get PDF
    This paper focuses on the analysis of modeling the growth rate of private equity investments and determining its related underlying factors. We calculate the growth rate based on the formula presented by Takahashi and Alexander (2001) and then model the growth rate to be related to the cumulative contribution rate and growth rate of price and earnings(with some lags) in public equity market. First we test the reliability of the model constructed by Hoek using the data of US private equity market from 1990 to 2002. Then we update the dataset up to 2006 for both US and European markets and redo the ordinary linear regression to test the reliability of our newly constructed model. We find that Hoek?s model is not quite reliable and persuasive in associating the growth rate of US private equity market to excess stock market return. In contrast, based on the derivation of change in net asset value (NAV) and results of statistical tests, the growth rate of US and European private equity markets seem to only depend on changes in the price of public equity markets but with the lag of one year for the US market and three years for European market

    Constrained CycleGAN for Effective Generation of Ultrasound Sector Images of Improved Spatial Resolution

    Full text link
    Objective. A phased or a curvilinear array produces ultrasound (US) images with a sector field of view (FOV), which inherently exhibits spatially-varying image resolution with inferior quality in the far zone and towards the two sides azimuthally. Sector US images with improved spatial resolutions are favorable for accurate quantitative analysis of large and dynamic organs, such as the heart. Therefore, this study aims to translate US images with spatially-varying resolution to ones with less spatially-varying resolution. CycleGAN has been a prominent choice for unpaired medical image translation; however, it neither guarantees structural consistency nor preserves backscattering patterns between input and generated images for unpaired US images. Approach. To circumvent this limitation, we propose a constrained CycleGAN (CCycleGAN), which directly performs US image generation with unpaired images acquired by different ultrasound array probes. In addition to conventional adversarial and cycle-consistency losses of CycleGAN, CCycleGAN introduces an identical loss and a correlation coefficient loss based on intrinsic US backscattered signal properties to constrain structural consistency and backscattering patterns, respectively. Instead of post-processed B-mode images, CCycleGAN uses envelope data directly obtained from beamformed radio-frequency signals without any other non-linear postprocessing. Main Results. In vitro phantom results demonstrate that CCycleGAN successfully generates images with improved spatial resolution as well as higher peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) compared with benchmarks. Significance. CCycleGAN-generated US images of the in vivo human beating heart further facilitate higher quality heart wall motion estimation than benchmarks-generated ones, particularly in deep regions

    xFx_F Dependence of Drell-Yan Transverse Moemtum Broadening

    Full text link
    We analyze xFx_F dependence of Drell-Yan transverse momentum broadening in hadron-nucleus collisions. In terms of generalized factorization theorem, we show that the xFx_F dependence of transverse momentum broadening, Δ<qT2>(xF) \Delta < q_T^2 > (x_F) , can be calculated in perturbative QCD. We demonstrate that Δ(xF)\Delta (x_F) is a good observable for studying the effects of initial-state multiple scattering and extracting quark-gluon correlation functions.Comment: 10 pages, 3 figure

    Intercellular protein–protein interactions at synapses

    Get PDF
    Chemical synapses are asymmetric intercellular junctions through which neurons send nerve impulses to communicate with other neurons or excitable cells. The appropriate formation of synapses, both spatially and temporally, is essential for brain function and depends on the intercellular protein-protein interactions of cell adhesion molecules (CAMs) at synaptic clefts. The CAM proteins link pre- and post-synaptic sites, and play essential roles in promoting synapse formation and maturation, maintaining synapse number and type, accumulating neurotransmitter receptors and ion channels, controlling neuronal differentiation, and even regulating synaptic plasticity directly. Alteration of the interactions of CAMs leads to structural and functional impairments, which results in many neurological disorders, such as autism, Alzheimer&apos;s disease and schizophrenia. Therefore, it is crucial to understand the functions of CAMs during development and in the mature neural system, as well as in the pathogenesis of some neurological disorders. Here, we review the function of the major classes of CAMs, and how dysfunction of CAMs relates to several neurological disorders.Cell BiologySCI(E)中国科学引文数据库(CSCD)[email protected]; [email protected]

    An approach to multiple attribute decision making based on the induced Choquet integral with fuzzy number intuitionistic fuzzy information

    Get PDF
    In this paper, we investigate the multiple attribute decision making problems with fuzzy number intuitionistic fuzzy information. Firstly, some operational laws of fuzzy number intuitionistic fuzzy values, score function and accuracy function of fuzzy number intuitionistic fuzzy values are introduced. Then, we have developed two fuzzy number intuitionistic fuzzy Choquet integral aggregation operators: induced fuzzy number intuitionistic fuzzy choquet ordered averaging (IFNIFCOA) operator and induced fuzzy number intuitionistic fuzzy choquet ordered geometric (IFNIFCOG) operator. The prominent characteristic of the operators is that they can not only consider the importance of the elements or their ordered positions, but also reflect the correlation among the elements or their ordered positions. We have studied some desirable properties of the IFNIFCOA and IFNIFCOG operators, such as commutativity, idempotency and monotonicity, and applied the IFNIFCOA and IFNIFCOGM operators to multiple attribute decision making with fuzzy number intuitionistic fuzzy information. Finally an illustrative example has been given to show the developed method
    • …
    corecore