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851.
Public perceptions of carbon capture and sequestration (CCS) and other low‐carbon electricity‐generating technologies may affect the feasibility of their widespread deployment. We asked a diverse sample of 60 participants recruited from community groups in Pittsburgh, Pennsylvania to rank 10 technologies (e.g., coal with CCS, natural gas, nuclear, various renewables, and energy efficiency), and seven realistic low‐carbon portfolios composed of these technologies, after receiving comprehensive and carefully balanced materials that explained the costs and benefits of each technology. Rankings were obtained in small group settings as well as individually before and after the group discussions. The ranking exercise asked participants to assume that the U.S. Congress had mandated a reduction in carbon dioxide emissions from power plants to be built in the future. Overall, rankings suggest that participants favored energy efficiency, followed by nuclear power, integrated gasification combined‐cycle coal with CCS and wind. The most preferred portfolio also included these technologies. We find that these informed members of the general public preferred diverse portfolios that contained CCS and nuclear over alternatives once they fully understood the benefits, cost, and limitations of each. The materials and approach developed for this study may also have value in educating members of the general public about the challenges of achieving a low‐carbon energy future. 相似文献
852.
853.
B.J. Hicks S.J. Culley C.A. McMahon P. Powell 《Journal of Engineering and Technology Management》2010,27(1-2):52-73
The benefits of integrated enterprise-wide information systems (IS), such as Enterprise Resource Planning (ERP) systems, are widely accepted. The implementation of such systems in large organisations is established with many in their second or third generation. However, in small to medium-sized enterprises (SMEs) the maturity and extent of their IS infrastructure is less clear. In engineering SMEs, this infrastructure needs to support not only business processes but also the activities of design and manufacture.In this case study, our goal is to provide a better understanding of current IS infrastructure, the functional elements of IS infrastructure, integration and expenditures are explored in ten engineering SMEs. A model of IS functionality is developed and used to identify and classify functional elements within the firms and to compare and contrast the IS infrastructures. The findings are contrasted with the SME literature and conclusions and implications developed. 相似文献
854.
One of the difficulties in evaluating leadership development is measuring whether and how people change over the time period of the leadership development initiative. Even when change over time is an inherent part of the design and evaluation of leadership development, events may occur outside of the control of evaluators that limit the effectiveness of adequately and accurately assessing change over time. With data from a leadership development initiative designed to account for change over time, this article suggests hierarchical linear modeling (HLM) as a multilevel methodological technique to assess change over time in a leadership development context. This article will use real change over time data from a leadership development initiative and discuss the logic and rationale of HLM. We use HLM as an example of a multilevel methodological tool to investigate typical change over time questions in leadership development evaluation. 相似文献
855.
Two studies were conducted to quantitatively and qualitatively examine supervisor–subordinate differences in perceptions concerning the quality of their LMX relationship. The results provided strong support for a lack of construct convergence between these two perspectives. Specifically, the findings suggest that leaders tend to focus more on task-oriented subdimensions and tend to give them greater weight when evaluating LMX relationships. However, subordinates are more oriented toward the social aspects of the relationship and perceive them as more important. This differential pattern was found to be generalizable across gender, race, and industry types. 相似文献
856.
Chien‐Ming Chen Yeming Gong Ren B.M. De Koster Jo A.E.E. Van Nunen 《Production and Operations Management》2010,19(1):70-82
This paper develops a novel framework to evaluate the integral performance of order picking systems with different combinations of storage and order picking policies. The warehousing literature on order picking mostly considers minimizing either elapsed time or distance as the sole objective, whereas warehouse managers in a supply chain have to look beyond single‐dimensional performance and consider trade‐offs among different criteria. Thus managers still need a unified and efficient framework to select a portfolio of appropriate order picking policies from a multi‐criteria and contextual perspective. Our framework—combining data envelopment analysis, ranking and selection, and multiple comparisons—provides an efficient methodology to simultaneously analyze several interrelated problems in order picking systems with multiple performance attributes, such as service levels and operational costs. We demonstrate our approach through comprehensive evaluations of order picking policies in three low‐level, picker‐to‐parts rectangular warehouses facing demand variations. 相似文献
857.
Ruud H. Teunter M. Zied Babai Aris A. Syntetos 《Production and Operations Management》2010,19(3):343-352
ABC inventory classifications are widely used in practice, with demand value and demand volume as the most common ranking criteria. The standard approach in ABC applications is to set the same service level for all stock keeping units (SKUs) in a class. In this paper, we show (for three large real life datasets) that the application of both demand value and demand volume as ABC ranking criteria, with fixed service levels per class, leads to solutions that are far from cost optimal. An alternative criterion proposed by Zhang et al. performs much better, but is still considerably outperformed by a new criterion proposed in this paper. The new criterion is also more general in that it can take criticality of SKUs into account. Managerial insights are obtained into what class should have the highest/lowest service level, a topic that has been disputed in the literature. 相似文献
858.
859.
Jason Abrevaya Jerry A. Hausman Shakeeb Khan 《Econometrica : journal of the Econometric Society》2010,78(6):2043-2061
A unifying framework to test for causal effects in nonlinear models is proposed. We consider a generalized linear‐index regression model with endogenous regressors and no parametric assumptions on the error disturbances. To test the significance of the effect of an endogenous regressor, we propose a statistic that is a kernel‐weighted version of the rank correlation statistic (tau) of Kendall (1938). The semiparametric model encompasses previous cases considered in the literature (continuous endogenous regressors (Blundell and Powell (2003)) and a single binary endogenous regressor (Vytlacil and Yildiz (2007))), but the testing approach is the first to allow for (i) multiple discrete endogenous regressors, (ii) endogenous regressors that are neither discrete nor continuous (e.g., a censored variable), and (iii) an arbitrary “mix” of endogenous regressors (e.g., one binary regressor and one continuous regressor). 相似文献
860.
Per Krusell Burhanettin Kuruu Anthony A. Smith 《Econometrica : journal of the Econometric Society》2010,78(6):2063-2084
We study optimal taxation when consumers have temptation and self‐control problems. Embedding the class of preferences developed by Gul and Pesendorfer into a standard macroeconomic setting, we first prove, in a two‐period model, that the optimal policy is to subsidize savings when consumers are tempted by “excessive” impatience. The savings subsidy improves welfare because it makes succumbing to temptation less attractive. We then study an economy with a long but finite horizon which nests, as a special case, the Phelps–Pollak–Laibson multiple‐selves model (thereby providing guidance on how to evaluate welfare in this model). We prove that when period utility is logarithmic, the optimal savings subsidies increase over time for any finite horizon. Moreover, as the horizon grows large, the optimal policy prescribes a constant subsidy, in contrast to the well known Chamley–Judd result. 相似文献