51,479 research outputs found
Robust active heave compensated winch-driven overhead crane system for load transfer in marine operation
Active heave compensation (AHC) is important for load transfer in marine operation using the overhead crane system (OCS). The control of marine OCS aims to continuously regulate the displacement of the cart and the payload sway angle, whilst at the same time, maintaining the gap between the payload and the vessel main deck at a desirable and safe distance. As the marine OHC system is to be operated in a continuously changing environment, with plenty inevitable disturbances and undesirable loads, a robust controller, i.e., active force control (AFC) is thus greatly needed to promote accuracy and robustness features into the controllability of OCS in rough working environment. This paper highlights a novel method for controlling the payload in an OCS based on the combination of both AFC and AHC. Results from the simulation study clearly indicate that the performance of OCS can be greatly improved by the proposed robust AFC controller, as compared with the classical PID controller scheme
Studies of Neutrino-Electron Scattering at the Kuo-Sheng Reactor Neutrino Laboratory
Studies on electron antineutrino-electron elastic scattering were performed
using a 200-kg CsI(Tl) scintillating crystal detector array at the Kuo-Sheng
Nuclear Power Plant in Taiwan. The measured cross section of R(exp) = [1.00 +-
0.32(stat)]xR(SM) is consistent with the Standard Model expectation and the
corresponding weak mixing angle derived is sin2T = 0.24 +- 0.05 (stat). The
results are consistent with a destructive interference effect between neutral
and charged-currents in this process. Limits on neutrino magnetic moment of
mu(nu_(e)) < 2.0 x 10^(-10) mu_(B) at 90% confidence level and on electron
antineutrino charge radius of r^(2) < (0.12 +- 2.07)x10^(-32) cm^2 were also
derived.Comment: Parallel talk at ICHEP08, Philadelphia, USA, July 2008. 4 pages,
LaTex, 4 eps figure
Do External Auditors Perform a Corporate Governance Role in Emerging Markets? Evidence from East Asia
In emerging markets, the concentration of corporate ownership has created agency conflicts between controlling owners and minority shareholders. Conventional corporate control mechanisms such as boards of directors and takeovers are typically weak in containing the agency problem. This study examines whether external independent auditors could be employed as monitors and as bonding mechanisms to alleviate the agency conflict. Using a broad sample of firms from eight East Asian economies, we document that firms are more likely to employ Big Five auditors when they are more subject to the agency problem imbedded in their ultimate ownership structure. One possible reason that this documented relation between auditor choice and the agency problem is more evident than the inconsistent results using U.S. and U.K. data is that alternative governance mechanisms are limited in East Asia. In addition, among East Asian auditees subject to the agency problem, Big Five auditors charge a higher fee and set a lower audit modification threshold while non-Big Five auditors do not. Taken together, the evidence suggests that Big Five auditors in emerging markets do have a corporate governance role.http://deepblue.lib.umich.edu/bitstream/2027.42/39784/3/wp400.pd
Highlights of the TEXONO Research Program on Neutrino and Astroparticle Physics
This article reviews the research program and efforts for the TEXONO
Collaboration on neutrino and astro-particle physics. The ``flagship'' program
is on reactor-based neutrino physics at the Kuo-Sheng (KS) Power Plant in
Taiwan. A limit on the neutrino magnetic moment of \munuebar < 1.3 X 10^{-10}
\mub} at 90% confidence level was derived from measurements with a high purity
germanium detector. Other physics topics at KS, as well as the various R&D
program, are discussedComment: 10 pages, 9 figures, Proceedings of the International Symposium on
Neutrino and Dark Matter in Nuclear Physics (NDM03), Nara, Japan, June 9-14,
200
AERODYNAMIC CHARACTERISTICS OF TWO RECTANGULAR-PLAN-FORM, ALLMOVABLE CONTROLS IN COMBINATION WITH A SLENDER BODY OF REVOLUTION AT MACH NUMBERS FROM 3.00 TO 6.25
Aerodynamic characteristics of rectangular planform, all-movable controls combined with slender body of revolution at mach 3 to 6.2
Spin-Seebeck effect in a strongly interacting Fermi gas
We study the spin-Seebeck effect in a strongly interacting, two-component
Fermi gas and propose an experiment to measure this effect by relatively
displacing spin up and spin down atomic clouds in a trap using spin-dependent
temperature gradients. We compute the spin-Seebeck coefficient and related
spin-heat transport coefficients as functions of temperature and interaction
strength. We find that when the inter-spin scattering length becomes larger
than the Fermi wavelength, the spin-Seebeck coefficient changes sign as a
function of temperature, and hence so does the direction of the
spin-separation. We compute this zero-crossing temperature as a function of
interaction strength and in particular in the unitary limit for the inter-spin
scattering
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