1,495 research outputs found
Trust, Organizational Controls, Knowledge Acquisition from the Foreign Parents, and Performance in Vietnamese International Joint Ventures
Successful adaptation in strategic alliances "calls for a delicate balance between the twin virtues of reliability and flexibility" [Parkhe 1998]. On one hand, the joint venture must be flexible enough to respond to the uncertainties of competitive business environments because it is not feasible to plan for every possible contingency. Yet, on the other hand, unfettered flexibility invites dysfunctional behavior, such as opportunism and complacency. This delicate balance accompanies a parallel balance between trust and control of the joint venture. The primary goal of this study is to empirically examine this relationship in the context of Vietnamese international joint ventures (IJVs) by building on the model of knowledge acquisition and performance in IJVs established by Lyles and Salk [1996]. This study makes three major contributions to the literature. First it confirms several findings of the original Lyles and Salk study [1996]. Second, we strengthen Lyles and Salk's original model by incorporating multiple measures of both interorganizational trust and control as independent variables. Finally, this study represents one of the first in-depth examinations of business in the emerging Vietnamese economy.http://deepblue.lib.umich.edu/bitstream/2027.42/39713/3/wp329.pd
Synthesis and application of porous organic polymers for removal of pollutants from wastewater
Trust, Organizational Controls, Knowledge Acquisition from the Foreign Parents, and Performance in Vietnamese International Joint Ventures
Successful adaptation in strategic alliances "calls for a delicate balance between the twin virtues of reliability and flexibility" [Parkhe 1998]. On one hand, the joint venture must be flexible enough to respond to the uncertainties of competitive business environments because it is not feasible to plan for every possible contingency. Yet, on the other hand, unfettered flexibility invites dysfunctional behavior, such as opportunism and complacency. This delicate balance accompanies a parallel balance between trust and control of the joint venture. The primary goal of this study is to empirically examine this relationship in the context of Vietnamese international joint ventures (IJVs) by building on the model of knowledge acquisition and performance in IJVs established by Lyles and Salk [1996]. This study makes three major contributions to the literature. First it confirms several findings of the original Lyles and Salk study [1996]. Second, we strengthen Lyles and Salk's original model by incorporating multiple measures of both interorganizational trust and control as independent variables. Finally, this study represents one of the first in-depth examinations of business in the emerging Vietnamese economy.
Gravitational lens candidates in the E-CDFS
We report ten lens candidates in the E-CDFS from the GEMS survey. Nine of the
systems are new detections and only one of the candidates is a known lens
system. For the most promising five systems including the known lens system, we
present results from preliminary lens mass modelling, which tests if the
candidates are plausible lens systems. Photometric redshifts of the candidate
lens galaxies are obtained from the COMBO-17 galaxy catalog. Stellar masses of
the candidate lens galaxies within the Einstein radius are obtained by using
the -band luminosity and the color-based stellar mass-to-light ratios.
As expected, the lensing masses are found to be larger than the stellar masses
of the candidate lens galaxies. These candidates have similar dark matter
fractions as compared to lenses in SLACS and COSMOS. They also roughly follow
the halo mass-stellar mass relation predicted by the subhalo abundance matching
technique. One of the candidate lens galaxies qualifies as a LIRG and may not
be a true lens because the arc-like feature in the system is likely to be an
active region of star formation in the candidate lens galaxy. Amongst the five
best candidates, one is a confirmed lens system, one is a likely lens system,
two are less likely to be lenses and the status of one of the candidates is
ambiguous. Spectroscopic follow-up of these systems is still required to
confirm lensing and/or for more accurate determination of the lens masses and
mass density profiles.Comment: 12 pages, 5 figures, 3 tables, ApJ accepte
Skycorr: A general tool for spectroscopic sky subtraction
Airglow emission lines, which dominate the optical-to-near-IR sky radiation,
show strong, line-dependent variability on various time scales. Therefore, the
subtraction of the sky background in the affected wavelength regime becomes a
problem if plain sky spectra have to be taken at a different time as the
astronomical data. A solution of this issue is the physically motivated scaling
of the airglow lines in the plain sky data to fit the sky lines in the object
spectrum. We have developed a corresponding instrument-independent approach
based on one-dimensional spectra. Our code skycorr separates sky lines and
sky/object continuum by an iterative approach involving a line finder and
airglow line data. The sky lines are grouped according to their expected
variability. The line groups in the sky data are then scaled to fit the sky in
the science data. Required pixel-specific weights for overlapping groups are
taken from a comprehensive airglow model. Deviations in the wavelength
calibration are corrected by fitting Chebyshev polynomials and rebinning via
asymmetric damped sinc kernels. The scaled sky lines and the sky continuum are
subtracted separately. VLT X-Shooter data covering time intervals from two
minutes to about one year were selected to illustrate the performance. Except
for short time intervals of a few minutes, the sky line residuals were several
times weaker than for sky subtraction without fitting. Further tests show that
skycorr performs consistently better than the method of Davies (2007) developed
for VLT SINFONI data.Comment: 17 pages, 18 figures, accepted for publication in A&
Molecfit: A general tool for telluric absorption correction II. Quantitative evaluation on ESO-VLT X-Shooter spectra
Context: Absorption by molecules in the Earth's atmosphere strongly affects
ground-based astronomical observations. The resulting absorption line strength
and shape depend on the highly variable physical state of the atmosphere, i.e.
pressure, temperature, and mixing ratio of the different molecules involved.
Usually, supplementary observations of so-called telluric standard stars (TSS)
are needed to correct for this effect, which is expensive in terms of telescope
time. We have developed the software package molecfit to provide synthetic
transmission spectra based on parameters obtained by fitting narrow ranges of
the observed spectra of scientific objects. These spectra are calculated by
means of the radiative transfer code LBLRTM and an atmospheric model. In this
way, the telluric absorption correction for suitable objects can be performed
without any additional calibration observations of TSS. Aims: We evaluate the
quality of the telluric absorption correction using molecfit with a set of
archival ESO-VLT X-Shooter visible and near-infrared spectra. Methods: Thanks
to the wavelength coverage from the U to the K band, X-Shooter is well suited
to investigate the quality of the telluric absorption correction with respect
to the observing conditions, the instrumental set-up, input parameters of the
code, the signal-to-noise of the input spectrum, and the atmospheric profiles.
These investigations are based on two figures of merit, I_off and I_res, that
describe the systematic offsets and the remaining small-scale residuals of the
corrections. We also compare the quality of the telluric absorption correction
achieved with moelcfit to the classical method based on a telluric standard
star. (Abridged)Comment: Acc. by A&A; Software available via ESO:
http://www.eso.org/sci/software/pipelines/skytools
Biomass and Wood Properties of Young Silver Maple Clones
Biomass properties were determined to characterize the differences between young silver maple clones as an energy source or fiber source feedstock. Size varied significantly among 25 maple sources evaluated, but larger trees generally had the better survival, which is highly important in clonal comparisons. Characteristics of the wood were similar to those of soft hardwoods; the mean value of gross heat of combustion was 19.6 kJ/g; the fiber length was relatively short (0.74 mm); the ash content was 0.291; and the specific gravity was 0.43. Clonal differences were significant
Molecfit: A general tool for telluric absorption correction. I. Method and application to ESO instruments
Context: The interaction of the light from astronomical objects with the
constituents of the Earth's atmosphere leads to the formation of telluric
absorption lines in ground-based collected spectra. Correcting for these lines,
mostly affecting the red and infrared region of the spectrum, usually relies on
observations of specific stars obtained close in time and airmass to the
science targets, therefore using precious observing time. Aims: We present
molecfit, a tool for correcting for telluric absorption lines based on
synthetic modelling of the Earth's atmospheric transmission. Molecfit is
versatile and can be used with data obtained with various ground-based
telescopes and instruments. Methods: Molecfit combines a publicly available
radiative transfer code, a molecular line database, atmospheric profiles, and
various kernels to model the instrument line spread function. The atmospheric
profiles are created by merging a standard atmospheric profile representative
of a given observatory's climate, of local meteorological data, and of
dynamically retrieved altitude profiles for temperature, pressure, and
humidity. We discuss the various ingredients of the method, its applicability,
and its limitations. We also show examples of telluric line correction on
spectra obtained with a suite of ESO Very Large Telescope (VLT) instruments.
Results: Compared to previous similar tools, molecfit takes the best results
for temperature, pressure, and humidity in the atmosphere above the observatory
into account. As a result, the standard deviation of the residuals after
correction of unsaturated telluric lines is frequently better than 2% of the
continuum. Conclusion: Molecfit is able to accurately model and correct for
telluric lines over a broad range of wavelengths and spectral resolutions.
(Abridged)Comment: 18 pages, 13 figures, 5 tables, accepted for publication in Astronomy
and Astrophysic
Investigating the Filled Gel Model in Cheddar Cheese Through Use of Sephadex Beads
Cheese can be modeled as a filled gel whereby milkfat globules are dispersed in a casein gel network. We determined the filler effects using Sephadex beads (GE Healthcare Life Sciences, Pittsburgh, PA) as a model filler particle. Ideally, such a model could be used to test novel filler particles to replace milkfat in low-fat cheese. Low-filler (6% particles), reduced-filler (16%), and full-filler (33%) cheeses were produced using either Sephadex beads of varying sizes (20 to 150 μm diameter) or milkfat. Small- and large-strain rheological tests were run on each treatment at 8, 12, and 18 wk after cheese manufacturing. Differences in rheological properties were caused primarily by the main effects of filler volume and type (milkfat vs. Sephadex), whereas filler size had no obvious effect. All treatments showed a decrease in deformability and an increase in firmness as filler volume increased above 25%, although the beads exhibited a greater reinforcing effect and greater energy recovery than milkfat
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