• Journal of Korean Society of Rural Planning
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• v.23 no.4
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• pp.111-126
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• 2017

This study analyzes the impacts of agricultural water shortages in Korea using a combined top-down and bottom-up model. A multi-region multi-output agricultural sector model with detailed descriptions of production technologies and water and land resource constraints has been combined with a standard CGE model. The impacts of four different water shortage scenarios were simulated. It is shown that an active adaptation of crop choices occurs in even the regions with relatively abundant water resources in order to respond to the change in relative output prices caused by water shortages. We found that although the losses in production values are not quite large despite water shortages due to the price feedbacks, the loss in GDP is substantial. We show that our combined approach has advantages in deriving region and product specific production effects as well as the overall GDP loss effect of water shortages.

• The Journal of the Korea Contents Association
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• v.20 no.7
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• pp.302-315
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• 2020

The issue concerning how to integrate with the needs of sustainable development according to Crime Prevention Through Environmental Design(CPTED) theory still continues in the development process of the third-generation theory at the present stage. In addition, the issue is under worldwide controversy and discussion. What is more noteworthy is that the viewpoints under debate and discussion have an influence on the mutual effect and relationship between the theoretical model and the principles in the theoretical model, and the influence can never be underestimated. After a mastery of the overall context of theoretical development, it is believed in this study that the identity of CPTED theory development can provide a diverse understanding dimension and a communication method between the environment and environmental users. On the basis of identity the development of CPTED theory, the crime prevention design mode of CPTED needs to connect different dimensions of sustainability, with the design goal of livability as the starting point, the Top-down model to adjust the safety of the environment. By no means can the environmental condition be improved by solely relying on the previous physical design method in virtue of Bottom-up model. Therefore, in this study, the identity of CPTED will be set as the core combined with Top-down crime prevention design model to propose a visual proposal for the reconstitution of the theoretical model, rather than supplementing the application of the contents or principles at a certain stage. Hence, it is expected to provide reference and enlightenment for the sustainable development of CPTED theory.

• Journal of Powder Materials
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• v.15 no.5
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• pp.365-370
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• 2008

In this study, bottom-up powder processing and top-down severe plastic deformation processing approaches were combined in order to achieve both full density and grain refinement with least grain growth. The numerical modeling of the powder process requires the appropriate constitutive model for densification of the powder materials. The present research investigates the effect of representative powder yield function of the Shima-Oyane model and the critical relative density model. It was found that the critical relative density model is better than the Shima-Oyane model for powder densification behavior, especially for initial stage.