142 research outputs found

    Linking Value Chain Costs To Products And Customers: Survey And Evaluation Of Large U.S. Manufacturing Firms’ Current Practices

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    Success in a competitive environment requires effectively selecting an optimal mix of value chain activities. Despite the fact that corporate executives need to understand the costs and benefits of supporting particular products and customers, little empirical evidence is available on how, and how well, companies are linking their value chain costs to these two cost objects. The results of this study, based on responses to a survey of 120 large U.S. manufacturing companies, indicate that firms tend to link their value chain costs to products/product lines more than to customers/customer classes. For both cost objects, most of the cost allocation bases used is volume-based. These findings suggest that while there is attention to the value chain costs, there is room for increasing the proportion of costs traced to products and customers and for expanding the use of non-volume allocation bases

    An Exploratory Study on Benifits and Success Factors of Information Technology Applications

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    This paper aims first, to explore the extent of benefits at different levels of IT applications in developing nations have realized. Second, this paper identifies those factors and/or processes associated with relative success and failure. This study collected data from fifty-seven firms in Taiwan using the mail survey method. Based on the Venkatraman’s (1994) levels of IT applications, six archetypes were developed to measure IT implementation (the first three stages represent evolutionary levels, while the last three represent revolutionary levels). Results indicated that a majority of firms are at the evolutionary levels of IT applications but over ninety percent of sample firms advanced IT applications within a three-year time frame. Despite the transformation, respondents perceived a low degree of variation in the realized benefits from IT applications and no significant differences existed between benefits derived from evolutionary and revolutionary levels of IT applications. Exceptions to this were benefits derived from reengineering the mix of internal value chain activities and IT applications on operations. Results from regression analysis indicated that success of IT applications was best determined by behavioral and organizational variables rather than by technical variables

    Constraining Aerosol Optical Models Using Ground-Based, Collocated Particle Size and Mass Measurements in Variable Air Mass Regimes During the 7-SEAS/Dongsha Experiment

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    During the spring of 2010, NASA Goddard's COMMIT ground-based mobile laboratory was stationed on Dongsha Island off the southwest coast of Taiwan, in preparation for the upcoming 2012 7-SEAS field campaign. The measurement period offered a unique opportunity for conducting detailed investigations of the optical properties of aerosols associated with different air mass regimes including background maritime and those contaminated by anthropogenic air pollution and mineral dust. What appears to be the first time for this region, a shortwave optical closure experiment for both scattering and absorption was attempted over a 12-day period during which aerosols exhibited the most change. Constraints to the optical model included combined SMPS and APS number concentration data for a continuum of fine and coarse-mode particle sizes up to PM2.5. We also take advantage of an IMPROVE chemical sampler to help constrain aerosol composition and mass partitioning of key elemental species including sea-salt, particulate organic matter, soil, non sea-salt sulphate, nitrate, and elemental carbon. Our results demonstrate that the observed aerosol scattering and absorption for these diverse air masses are reasonably captured by the model, where peak aerosol events and transitions between key aerosols types are evident. Signatures of heavy polluted aerosol composed mostly of ammonium and non sea-salt sulphate mixed with some dust with transitions to background sea-salt conditions are apparent in the absorption data, which is particularly reassuring owing to the large variability in the imaginary component of the refractive indices. Extinctive features at significantly smaller time scales than the one-day sample period of IMPROVE are more difficult to reproduce, as this requires further knowledge concerning the source apportionment of major chemical components in the model. Consistency between the measured and modeled optical parameters serves as an important link for advancing remote sensing and climate research studies in dynamic aerosol-rich environments like Dongsha

    Enhanced ex vivo expansion of adult mesenchymal stem cells by fetal mesenchymal stem cell ECM

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    Large-scale expansion of highly functional adult human mesenchymal stem cells (aMSCs) remains technologically challenging as aMSCs lose self renewal capacity and multipotency during traditional long-term culture and their quality/quantity declines with donor age and disease. Identification of culture conditions enabling prolonged expansion and rejuvenation would have dramatic impact in regenerative medicine. aMSC-derived decellularized extracellular matrix (ECM) has been shown to provide such microenvironment which promotes MSC self renewal and “stemness”. Since previous studies have demonstrated superior proliferation and osteogenic potential of human fetal MSCs (fMSCs), we hypothesize that their ECM may promote expansion of clinically relevant aMSCs. We demonstrated that aMSCs were more proliferative (∼1.6×) on fMSC-derived ECM than aMSC-derived ECMs and traditional tissue culture wares (TCPS). These aMSCs were smaller and more uniform in size (median ± interquartile range: 15.5 ± 4.1 μm versus 17.2 ± 5.0 μm and 15.5 ± 4.1 μm for aMSC ECM and TCPS respectively), exhibited the necessary biomarker signatures, and stained positive for osteogenic, adipogenic and chondrogenic expressions; indications that they maintained multipotency during culture. Furthermore, fMSC ECM improved the proliferation (∼2.2×), size (19.6 ± 11.9 μm vs 30.2 ± 14.5 μm) and differentiation potential in late-passaged aMSCs compared to TCPS. In conclusion, we have established fMSC ECM as a promising cell culture platform for ex vivo expansion of aMSCs.Singapore-MIT Alliance for Research and Technolog

    Non-Standard Errors

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    In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty: Non-standard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for better reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants

    Alternative splicing: the pledge, the turn, and the prestige

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