Using a three‐sector general equilibrium model with non‐traded goods, we investigate the impact of foreign direct investment on the real wages of skilled and unskilled workers. We show that foreign direct investment increases the real wages of skilled and unskilled workers alike, but widens the gap between the two under plausible conditions. 相似文献
This paper develops a polynomial algorithm for obtaining dynamic economic lot sizes in a single product multiperiod production system with the objective of minimizing total production and inventory costs over T periods. It is assumed that production costs are linear, inventory costs are concave, setup costs are zero and backlogging is not permitted in all periods. Moreover, the unit production cost is a stochastic variable, which is evolved according to a continuous-time Markov process over the planning horizon. The model is formulated as a stochastic dynamic programming (DP) optimization with the state variable being unit production cost. Then, it is solved using the backward dynamic programming approach. To justify the application of the proposed model, two practical cases are presented. 相似文献
Significant oil and gas firm market value is derived from their physical reserve quantum, assets which are not recorded on their statements of financial position. This article provides empirical evidence regarding voluntary disclosure of such reserves in line with the previously unresearched UK sector with regard to its unique reporting guidelines. The study considers both the reporting of the reserve quantum and the quality of that reporting. This article seeks to inform the International Accounting Standards Board’s (IASB’s) on-going consideration of mineral resource reporting. Listed companies are considered to evidence forms of reserve disclosure with a logistical regression approach applied to measure determinants of reporting. The risk associated with mineral reporting reserves is hypothesized as the key disclosure driver whilst controlling other relevant variables. The majority of firms disclosed reserve quantities in some form but only a minority disclosed in line with recommended practice, disclosure quality being more variable between companies. The findings indicate that a voluntary disclosure approach is ineffective, partially explained by agency related behaviour. Risk, proxied by the stage of production, drives reserve disclosure showing that producer firms are more likely to disclose reserve quantum balances and of a significantly higher quality. 相似文献
Water Resources Management - Due to an oversight, 10 (ten) references were cited incorrectly in the reference list of the original publication. The first names were used instead of the last names... 相似文献
A field‐scale analysis for leachate flow was done for Sections 1/9 and 6/7 of the Fresh Kills landfill at Staten Island, New York. The leachate monitoring programme included field data collection of the leachate mound level for a six‐month period. The monitoring points consisted of discretely screened piezometers and wells set at various depths down to the bottom of the landfill. The position of the iso‐leachate mound head lines, derived from the field data, represented and delineated the shape of the leachate mound inside the landfill. The field data of the leachate mound head were used in the analysis of the hydraulic properties of the refuse and leachate flow rates through Sections 1/9 and 6/7 of the landfill. Piezometers and wells installed near the existing leachate collection line in Section 1/9 helped establish the gradients from which a refined estimate of the hydraulic conductivity was made. From the leachate mound head contours and flow gradients, contributions of flow from different sections of the mound were identified. Finally, the leachate flow rates were computed using Darcy's law. 相似文献
The Estimation of suspended sediment concentration (SSC) is an important factor in river engineering, which is used as an indicator of land-use change, water quality studies, and all projects related to constructions in rivers. In this research, the M5 model tree and the Moderate Resolution Imaging Spectroradiometer (MODIS) data were utilized to estimate the SSC at Ahvaz station on the Karun River. In this study, 135 cloud-free images of the MODIS sensor on the Terra satellite were taken for days corresponding to field SSC data, during the years 2000 to 2015. Input parameters of the model tree in this study were flow discharge, derived from hydrological data, and red (R), near-infrared (NIR) bands, and NIR/R ratio extracted from MODIS imagery. The results of statistical analysis illustrate that the M5 model outperforms the sediment rating curve (SRC) method, which is the most common method of estimating suspended sediment load. The Nash-Sutcliffe efficiency index for the M5 model tree of 0.58 was achieved, which was much better than that of the SRC method (0.26). At high fluxes, the efficiency of the SRC method significantly reduced, while the model tree provides acceptable results. The global sensitivity analysis on the M5 model pointed out that 93% of output variance was established by the main effects of input parameters, and less than 7% belong to the interaction effects. 73% and 12% of output variance specified by the main effects of flow discharge and NIR/R ratio, respectively.
