• Korea-Australia Rheology Journal
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• v.20 no.2
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• pp.51-58
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• 2008

This paper describes a two-step Tikhonov regularization procedure for converting the steady shear data generated by parallel-disk viscometers, in the presence of wall slip, into a shear stress-shear rate function and a wall shear stress-slip velocity functions. If the material under test has a yield stress or a critical wall shear stress below which no slip is observed the method will also provide an estimate of these stresses. Amplification of measurement noise is kept under control by the introduction of two separate regularization parameters and Generalized Cross Validation is used to guide the selection of these parameters. The performance of this procedure is demonstrated by applying it to the parallel disk data of an oil-in-water emulsion, of a foam and of a mayonnaise.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.4
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• pp.467-474
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• 2004

A large-eddy simulation is performed for turbulent flow in a concentric annulus with the inner wall rotation at Re$\sub$Dh/=8900 for three rotation rates N=0.2145, 0.429 and 0.858. Main emphasis is placed on the inner wall rotation effect on near-wall turbulent structures. Near-wall turbulent structures close to the inner wall are scrutinized by computing the lower-order statistics. The anisotropy invariant map for the Reynolds stress tensor and the invariant function are illustrated to reveal the altered anisotropy in turbulent structure. Probability density functions of the splat/anti-splat process are explored to develop a sufficiently complete picture of the contributions of the flow events to turbulent production. The present numerical results show that the altered turbulent structures may be attributed to the centrifugal instability, which leads to the augmentation of sweep and ejection events.

• Journal of the Korea Furniture Society
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• v.22 no.1
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• pp.1-12
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• 2011

Recently, the studio which is urban housing form is rapidly growing up by new residential space according to increasing 1~2 person households form because of Modern members who have changing patterns of life and diversification of social values. The resident of the studio who lives or uses the space for a work such as students, office worker and soho-jok has various characters by a society nature changes and a regional peculiarity. The studio form and function is getting change according to variety trend changes and their life styles. The role and use of residential space also have variety such as the resident who lives in the studio. This study is to find the space utilization for them and reasonable housing solution in that structure, furniture and Wall Storage System of existing studio which is based on the common life patterns. The study's purpose is to propose the furniture design of changeable Wall Storage System according to the analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.710-713
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• 2003

The wall charge is major factor to determine the discharge characteristics. The minimum sustain voltage related to the wall charge decay were investigated as a function of aging time in AC plasma display panel. For the long time scale, the wall charge decay time is dependent on the aging time. The inverse time scale of the wall charge decay has the maximum value at around 3 hours aging time and then fell down.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.11
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• pp.1552-1561
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• 1997

In this numerical study, it is investigated for the ice-formation phenomena for water flow in a concentric tube. The freezing layers of ice in both the inner and outer wall of a concentric tube are simultaneously considered. In the solution strategy, the complete set of governing equations in both the solid and liquid regions are resolved. Numerical results are obtained by varying the inner/outer wall temperatures and Reynolds number. The results show that the inner/outer wall temperatures have the great effect on the thickness of the solidification layer thereof. The shapes of ice layer in both the inner and outer wall can be expressed as a function of inverse Graetz number. As the wall temperature in inner or outer tube decreases, the heat transfer coefficients in both inner and outer ice layer surfaces increase absolutely.

• Structural Engineering and Mechanics
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• v.51 no.3
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• pp.361-375
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• 2014

The main aim of this paper is to investigate the relationship between thickness and height of the axially symmetric cylindrical reinforced concrete (RC) walls by the help of a meta-heuristic optimization procedure. The material cost of the wall which includes concrete, reinforcement and formwork, was chosen as objective function of the optimization problem. The wall thickness, compressive strength of concrete and diameter of reinforcement bars were defined as design variables and tank volume, radius and height of the wall, loading condition and unit cost of material were defined as design constants. Numerical analyses of the wall were conducted by using superposition method (SPM) considering ACI 318-Building code requirements for structural concrete. The optimum wall thickness-height relationship was investigated under three main cases related with compressive strength of concrete and density of the stored liquid. According to the results, the proposed method is effective on finding the optimum design with minimum cost.

• Computers and Concrete
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• v.29 no.5
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• pp.279-283
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• 2022

The seismic analytic collapse fragility of soil nail wall structures with a shotcrete concrete covering is investigated in this paper. The finite element modeling process has been well described. The fragility function evaluates the link between ground motion intensities and the likelihood of reaching a specific level of damage. The soil nail wall has been subjected to incremental dynamic analysis (IDA) from medium to strong ground vibrations. The nonlinear dynamic analysis of the soil nail wall uses a set of 20 earthquake ground motions with varying PGAs. PGD is utilized as an intensity measure, the numerical findings demonstrate that the soil nailing wall reaction is particularly sensitive to earthquake intensity measure (IM).

• Structural Engineering and Mechanics
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• v.86 no.1
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• pp.85-92
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• 2023

This article examines the seismic vulnerability of soil nail wall structures. Detailed information regarding finite element modeling has been provided. The fragility function evaluates the relationship between ground motion intensities and the probability of surpassing a specific level of damage. The use of incremental dynamic analysis (IDA) has been applied to the soil nail wall against low to severe ground motions. In the nonlinear dynamic analysis of the soil nail wall, a set of twenty seismic ground motions with varying PGA ranges are used. The numerical results demonstrate that the soil-nailed wall reaction is extremely sensitive to earthquake ground vibrations under different intensity measures (IM). In addition, the analytical fragility curve is provided for various intensity values.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.43-55
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• 2017

The purpose of this study is to investigate the effect of traffic loads on retaining wall stability. There is insufficient research on lateral earth pressure on retaining wall due to traffic load. In addition, limited detailed designs of retaining wall for transportation including number of lanes of road, magnitudes of axle loads, and vehicle formations are available. Because the lateral earth pressure on the retaining wall due to traffic loads is a function of the lateral distance from retaining wall, the wall height, and the locations of lanes, the analysis of lateral load on retaining wall from traffic loads is performed with direct or indirect reflection of these factors. As a result of the analysis, lateral earth loads induced from traffics can be considered negligible if the lateral distance of traffic load from wall exceeds the height of retaining wall. Therefore, it is practically reasonable to consider traffic loads within a lateral distance between wall and traffic load of the height of retaining wall.

• 기술발표회
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• s.2006
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• pp.279-291
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• 2006

This study shows decision-making process for selection of cutoff wall on a wastewater treatment project. There are 10 different cut-off wall methods So, we examine the site to gather information for find appropriate methods. After using that information, 10 cutoff wall methods are reviewed for analysis. Through brainstorming, four alternatives are selected for design VE item. Following the standard VE process, we established performance criteria and evaluated function score(F) using questionnaire. The questionnaires, brainstorming and AHP method for weighting on performance criteria and evaluate function score increased the reliability of this selection process. Water Jet method, one of four methods, has the best function score(F=92.71) and the lease construction cost(as cost index 1,000). The value score also highest as 92.7, so we select the method. The result is value innovation type In addition, the authors try to calculate the environmental burden in selection process using LCA. We cannot conduct the full LCA as defined ISO, so perform Simple LCA In LCA result, the cut-off grouting has the least environmental burden as index 9.09E+01 and Water Jet method has following as the second. To selection best method to specific area and purpose, design VE/LCG process used as useful tool and it is needed to develop integrated method that evaluate VEILCC and LCA as one-set process.