41,490 research outputs found
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
Fresnel operator, squeezed state and Wigner function for Caldirola-Kanai Hamiltonian
Based on the technique of integration within an ordered product (IWOP) of
operators we introduce the Fresnel operator for converting Caldirola-Kanai
Hamiltonian into time-independent harmonic oscillator Hamiltonian. The Fresnel
operator with the parameters A,B,C,D corresponds to classical optical Fresnel
transformation, these parameters are the solution to a set of partial
differential equations set up in the above mentioned converting process. In
this way the exact wavefunction solution of the Schr\"odinger equation governed
by the Caldirola-Kanai Hamiltonian is obtained, which represents a squeezed
number state. The corresponding Wigner function is derived by virtue of the
Weyl ordered form of the Wigner operator and the order-invariance of Weyl
ordered operators under similar transformations. The method used here can be
suitable for solving Schr\"odinger equation of other time-dependent
oscillators.Comment: 6 pages, 2 figure
Effects of topological edge states on the thermoelectric properties of Bi nanoribbons
Using first-principles calculations combined with Boltzmann transport theory,
we investigate the effects of topological edge states on the thermoelectric
properties of Bi nanoribbons. It is found that there is a competition between
the edge and bulk contributions to the Seebeck coefficients. However, the
electronic transport of the system is dominated by the edge states because of
its much larger electrical conductivity. As a consequence, a room temperature
value exceeding 3.0 could be achieved for both p- and n-type systems when the
relaxation time ratio between the edge and the bulk states is tuned to be 1000.
Our theoretical study suggests that the utilization of topological edge states
might be a promising approach to cross the threshold of the industrial
application of thermoelectricity
Using schema transformation pathways for data lineage tracing
With the increasing amount and diversity of information available on the Internet, there has been a huge growth in information systems that need to integrate data from distributed, heterogeneous data sources. Tracing the lineage of the integrated data is one of the problems being addressed in data warehousing research. This paper presents a data lineage tracing approach based on schema transformation pathways. Our approach is not limited to one specific data model or query language, and would be useful in any data transformation/integration framework based on sequences of primitive schema transformations
Tuning the carrier concentration to improve the thermoelectric performance of CuInTe2 compound
The electronic and transport properties of CuInTe2 chalcopyrite are
investigated using density functional calculations combined with Boltzmann
theory. The band gap predicted from hybrid functional is 0.92 eV, which agrees
well with experimental data and leads to relatively larger Seebeck coefficient
compared with those of narrow-gap thermoelectric materials. By fine tuning the
carrier concentration, the electrical conductivity and power factor of the
system can be significantly optimized. Together with the inherent low thermal
conductivity, the ZT values of CuInTe2 compound can be enhanced to as high as
1.72 at 850 K, which is obviously larger than those measured experimentally and
suggests there is still room to improve the thermoelectric performance of this
chalcopyrite compound
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