1,495 research outputs found

    Trust, Organizational Controls, Knowledge Acquisition from the Foreign Parents, and Performance in Vietnamese International Joint Ventures

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    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

    Trust, Organizational Controls, Knowledge Acquisition from the Foreign Parents, and Performance in Vietnamese International Joint Ventures

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    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

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    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 zz-band luminosity and the VzV-z 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

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    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

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    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

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    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

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    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

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    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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