Browsing by Author "Huang, C"

Now showing 1 - 4 of 4
  • Thumbnail Image
    ItemOpen Access
    Estimation of seemingly unrelated tobit regressions via the em algorithm
    (Journal of Business and Economic Statistics, 1987-01-01) Sloan, FA; Huang, C; Adamache, K
    An expectation-maximum (EM) likelihood algorithm is used to estimate two seemingly unrelated Tobit regressions in which the dependent variables are truncated normal. An illustrative example on the determination of the life-health insurance and pension benefits is also given. © 1987 American Statistical Association.
  • Thumbnail Image
    ItemOpen Access
    Preservation of beam emittance in the presence of ion motion in future high-energy plasma-wakefield-based colliders.
    (Phys Rev Lett, 2010-04-16) Gholizadeh, R; Katsouleas, T; Muggli, P; Huang, C; Mori, W
    The preservation of beam quality in a plasma wakefield accelerator driven by ultrahigh intensity and ultralow emittance beams, characteristic of future particle colliders, is a challenge. The electric field of these beams leads to plasma ions motion, resulting in a nonlinear focusing force and emittance growth of the beam. We propose to use an adiabatic matching section consisting of a short plasma section with a decreasing ion mass to allow for the beam to remain matched to the focusing force. We use analytical models and numerical simulations to show that the emittance growth can be significantly reduced.
  • Thumbnail Image
    ItemOpen Access
    The paradox of openness revisited: Collaborative innovation and patenting by UK innovators
    (Research Policy, 2016-09-01) Arora, A; Athreye, S; Huang, C
    © 2016 The Authors.We revisit the "paradox of openness" in the literature which consists of two conflicting views on the link between patenting and open innovation - the spillover prevention and the organizational openness views. We use the data from the Survey of Innovation and Patent Use and the Community Innovation Survey (CIS6) in the UK to assess the empirical support for the distinct predictions of these theories. We argue that both patenting and external sourcing (openness) are jointly-determined decisions made by firms. Their relationship is contingent upon whether the firms are technically superior to their rivals and lead in the market or not. Leading firms are more vulnerable to unintended knowledge spillovers during collaboration as compared to followers, and consequently, the increase in patenting due to openness is higher for leaders than for followers. We develop a simple framework that allows us to formally derive the empirical implications of this hypothesis and test it by estimating whether the reduced form relationship between patenting and collaboration is stronger for leaders than for followers.
  • Thumbnail Image
    ItemOpen Access