• Advances in nano research
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• v.10 no.5
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• pp.493-507
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• 2021

This article focused on studying the buckling behavior of two-dimensional functionally graded (2D-FG) nanosize tubes, including porosity based on first shear deformation and higher-order theory of tube. The nano-scale tube is simulated based on the nonlocal gradient strain theory, and the general equations and boundary conditions are derived using Hamilton's principle for the Zhang-Fu's tube model (as higher-order theory) and Timoshenko beam theory. Finally, the derived equations are solved using a numerical method for both simply-supported and clamped boundary conditions. The parametric study is performed to study the effects of different parameters such as axial and radial FG power indexes, porosity parameter, nonlocal gradient strain parameters on the buckling behavior of di-dimensional functionally graded porous tube.

• Journal of Environmental Impact Assessment
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• v.3 no.1
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• pp.31-41
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• 1994

The choice of economic development over environmental protection has been used to explain the decline in the quality of the environment in developing countries. The authors reject this explanation and propose a theory of negligence to explain this decline. They point to the advantages of environmental impact assessments in dealing with the problem of negligence and presents case studies from four countries. Organizational models for Environmental Impact Assessments in Developing Countries are proposed as useful policy measures.

• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.42-42
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• 2000

• Proceedings of the Korea Water Resources Association Conference
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• 1995.05a
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• pp.238-244
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• 1995

• Journal of Korean Society of Environmental Engineers
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• v.35 no.5
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• pp.334-339
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• 2013

A pilot-scale sand-box experiment simulating a lateral of collector well used in riverbank filtration was performed, and hydraulic head distributions along the lateral were measured according to the various drawdowns at the well. The results of this experiment were compared to the predicted values obtained using a theory previously developed by Kim in order for its validation. This theory predicts the head loss in a large-scale lateral given the loss in a small-scale one, and to have actual values for comparison, the results from a lab-scale experiment previously performed by Kim were employed. Comparing the experimental values to the extrapolated value indeed confirmed the validity of the theory. A procedure to determine the hydraulic head distribution of a practical-scale lateral was also presented applying the theory to the experimental result of this study in an effort to show the process of lateral design for riverbank filtration.

• Journal of Korean Society of Rural Planning
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• v.15 no.4
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• pp.33-42
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• 2009

This study is aimed at the necessity application in 'Prototype' general concept on discovering cultural identity landscape of our national characteristics landscape research. Accordingly, It is considered landscape, fundamental concept, the prototypal landscape concept from previously researches that have been used. At the same time, the concept of prototypal landscape has been established by commenting a point of view which is defining previous researches that controverted prototypal landscape, then establish concept of prototypal landscape and derive attribute by comparing and considering similar terminology of prototypal landscape. Previously, research prototypal landscape in depth by applying defined concept of prototypal landscape and considering inherence ideological and environmental background prototypal figure and structure. Formation pattern of the prototypal landscape is classified in both philosophical formative primary factor from philosophy, religion and environmental formative factor of human that accumulated cultural life from a region and life. Examples of forming the prototypal landscape by philosophical formative factor are classified as 'Feng-Shui(the theory of divination based on topography)', 'Yin-Yang theory', 'Confucian idea theory' 'Philosophical Taoism', 'Buddhism theory' and 'Nature theory' then environmental formative factor are interpreted by 'Taekliji(determining of advantageous land)', 'Imwon(forest) economical geography', 'land use', 'topography' and 'terrain' as examples. This study is anticipating a new point of view and an establishment of reliable preservation to our characteristic of the prototypal landscape by considering concept of prototypal landscape and formative factor as studying limits of prototypal landscape and researching concentrated origination of the prototype.

• Journal of Environmental Science International
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• v.3 no.1
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• pp.31-38
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• 1994

The diffusion of the pollutants released into atmosphere is dependent on its chemical reaction, topography and micrometeorological characteristics. The purpose of the study is to investigate how much micrometeorological characteristics such as stability, wind speed and mixing height affect the diffusion of the air pollutants. For this purpose, this paper let 1) the basic theory be K-theory, 2) eddy diffusivity and wind speed be dependent on mixing height and stability, and 3) Grout method be used for numeric calculation. The result was 1) the more unstable condition, the higher mixing height and the higher wind speed we, the lower pollutants concentration appears, 2) the most intensive effect on the distribution of the pollutant concentration is the atmospheric stability.

• Interaction and multiscale mechanics
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• v.1 no.4
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• pp.423-435
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• 2008

This paper employs the reproducing kernel (RK) approximation for evaluation of field theory-based incompatibility tensor in a polycrystalline plasticity simulation. The modulation patterns, which is interpreted as mimicking geometrical-type dislocation substructures, are obtained based on the proposed method. Comparisons are made using FEM and RK based approximation methods among different support sizes and other evaluation conditions of the strain gradients. It is demonstrated that the evolution of the modulation patterns needs to be accurately calculated at each time step to yield a correct physical interpretation. The effect of the higher order strain derivative processing zone on the predicted modulation patterns is also discussed.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.752-759
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• 2006

Conglomerates and core-stones are the typical composite geomaterials that are composed of a weak matrix and a strong pebble part. In general, we couldn't analyze the composite geomaterials by using emperical rock classification methods. In the study, a series of analyses of elastic behavior of composite geomaterials are carried out by using homogenization theory. 45-case models are made with considering 3 kind of factors such as gravel content, size and strength of matrix. Those are applicable to various composite geomaterials of conglomerates and core-stones. The size of analysis model is large enough to exceed REV.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.159-168
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• 2018

In this study, a real-time grouting management system based on the clogging theory was established to manage injection procedure in real time. This system is capable of estimating hydraulic permeability with the passage of time as the grout permeates through the ground, and therefore, capable of estimating real time injection distance and flow rate. By adopting the Controlled Injection Pressure (CoIP) model, it was feasible to predict the grout permeation status with the elapse of time by consecutively updating the hydraulic gradient and flow rate estimated from a clogging-induced alteration of pore volume. Moreover, a method to estimate the volume of the fractured gap according to the reduction in injection pressure was proposed. The validity of the proposed system was successfully established by comparing the estimated values with the measured field data.