• The KSFM Journal of Fluid Machinery
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• v.8 no.5 s.32
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• pp.29-34
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• 2005

In this study, the effect of flow settling means on the performance of fan tester were numerically investigated by using a computational fluid dynamics (CFD). The airflow rate was calculated from the pressure differential across a flow nozzle in the measuring plane and the flow settling means were generally installed in the chamber of the fan tester to provide proper airflow patterns ahead of the measuring plane. The predicted nozzle differential pressures with uniform inlet velocities were compared with the values of the ANSI/AMCA 210-99 to verify the performance of the commercial CFD code CFX 5.6. The influence of flow settling means on the measurement of airflow rate in a fan tester were discussed with various porosities and inlet jet velocities. The results obtained show that the proper band of porosities exist to meet the AMCA standard in a specified inlet jet velocity.

• The KSFM Journal of Fluid Machinery
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• v.9 no.4 s.37
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• pp.43-48
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• 2006

In this study, the effect of flow settling means on the performance of fan tester were numerically investigated by using a computational fluid dynamics(CFD). The airflow rate was calculated from the pressure differential across a flow nozzle in the measuring plane and the flow settling means were generally installed in the chamber of the fan tester to provide proper airflow patterns ahead of the measuring plane. The predicted nozzle differential pressures with uniform inlet velocities were compared with the values of the ANSI/AMCA 210-99 to verify the performance of the commercial CFD code CFX 5.6. The influence of flow settling means on the measurement of airflow rate in a fan tester were discussed with various porosities and inlet jet velocities. The results obtained show that the proper band of porosities exist to meet the AMCA standard in a specified inlet jet velocity.

• Journal of Environmental Impact Assessment
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• v.19 no.5
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• pp.475-481
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• 2010

Lots of pollutants typically originating from urban transportation are accumulating on the paved surfaces during dry periods and are washed-off directly to the river during a storm. Also, paved surfaces are contributing to increase in peak flows and volume of stormwater flows. These are the main reasons why the water quality of rivers and lakes remain polluted and still below standards. Currently, several management practices are being applied in developed countries but the design standards are still lacking. This research was conducted to develop a treatment technology that can be useful to address the problems concerning runoff quality and quantity. A lab scale infiltration device consisting of a pretreatment tank and media zone was designed and tested for various flow regimes characterizing the low, average and high intensity rainfall. Based on the experiments, the high intensity flow resulted to increase in outflow event mean concentration (EMC) of pollutants, about twice as much as the average outflow EMC. However, 78 to 88% of the total suspended solids were captured and retained in the pretreatment tank because of sedimentation. The removal of heavy metals such as zinc and lead was greatly affected by the vertical placement of woodchip layer prior to the media zone. It was observed that the high carbon content (almost 50%) in the woodchip provided opportunity for enhancing its uptake of metal by adsorption. The findings implied that the reduction of pollutants can be greatly achieved by means of proper pretreatment to allow for settling of particles with a combination of using high carbon source media like woodchip and a geotextile mat to reduce the flow before filtering into the media zone and finally discharging to the drainage system.

• Management & Information Systems Review
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• v.37 no.2
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• pp.187-207
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• 2018

This study examines the negative relationship between accounting conservatism and excess executive compensation and examines whether their relationship increases as managerial incentive compensation intensity increases. For this purpose, a total of 2,755 company-years were selected for the analysis of the companies listed on the Korea Stock Exchange from December 2012 to 2016 as the final sample. The results of this study are as follows. First, there is a statistically significant negative relationship between accounting conservatism and manager overpayment. This implies that managers' incentives to distort future cash flow estimates by over booking assets or accounting profits in order to maximize their compensation when manager compensation is linked to firm performance. In this sense, accounting conservatism can reduce opportunistic behavior by restricting managerial accounting choices, which can be interpreted as a reduction in overpayment to managers. Second, we found that the relationship between accounting conservatism and excess executive compensation increases with the incentive compensation for accounting performance. The higher the managerial incentive compensation intensity of accounting performance is, the more likely it is that the manager has the incentive to make earnings adjustments. Therefore, the high level of incentive compensation for accounting performance means that the ex post settling up problem due to over-compensation can become serious. In this case, the higher the managerial incentive compensation intensity for accounting performance, the greater the role and utility of conservatism in manager compensation contracts. This study is based on the fact that it presents empirical evidence on the usefulness of accounting conservatism in managerial compensation contracts theoretically presented by Watts (2003) and the additional basis that conservatism can be used as a useful tool for investment decision.