• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.199-206
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• 2005

Engineers have performed slope stability analyses, including Limit Equilibrium Analysis, Finite Difference Analysis and Finite Element Analysis. Each analysis results in different Factor of Safety(FS) for slopes. The comparison of FS results from these stability analyses has been carried out for various conditions, such as geometry of slopes, dry and fully saturated soils, nail and anchor reinforcements. Standard deviations of FS calculated from various slope analyses are 0.03 to 0.04 and 0.22 to 0.48 for the slopes without and with nail or anchor reinforcement, respectively. Construction of tiered concrete retaining wall in addition to nail or anchor reinforcement increases FS of 12% to 29% for fully saturated soils.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.580-585
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• 2004

The purpose of this study is the stability evaluation of soil slope according to inclination of upper natural slope. Upper natural slope breeds loss of slope by inflow in slope of surface water by rainfal1 and f1uctuation of amount of materials in slope through method of cutting slope according to degree of inclination. Basis of standard inclination does not consider of inclination of upper natural slope and is presented uniformly. Therefore, in this study, analyzed stability of inclination of upper natural slope through limit equilibrium analysis. Result is same as following. First, safety factor through limit equilibrium analysis is almost direct decrease when gradient of soil slope is 1:1.2, 1:1.5. However, when gradient of soil slope is 1:1.0, 1:0.7, if sinclination of upper natural slope are $20^{\circ}$, it shows tendency that decrease of safety factor becomes low rapidly. Second, when when gradient of soil slope is fixed, inclination of upper natural slope increase tendency(maximum 3.0 times) that decrease of safety factor.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.3
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• pp.255-262
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• 2014

PURPOSE: This study was to investigate the effectiveness of TENS on balance in stroke patients by analyzing some components such as foot pressure, limit of stability and velocity sway after providing somatosensroy input using TENS. METHODS: Twenty five subjects participated and were randomly divided into two groups, TENS group (n=13) and control group (n=12) by the computer program. Interventions were given to subjects 5 days a week for four weeks. TENS group were treated with TENS for 60 minutes in addition to the conventional therapy which included 30-minute exercise and rehabilitation ergometer training for 15 minutes. Control group performed only conventional therapy. TENS was applied on the skin of soleus, tibialis anterior, tensor fascia latae and vastus medialis in affected side. Foot pressure, limit of stability and velocity sway for balance test were measured using Biorescue. RESULTS: TENS group was significantly increased limit of stability and foot pressure in affected side more than control group. And in eye closed condition, TENS group was significantly decreased velocity sway more than control group. CONCLUSION: The application of TENS is effective to improve the somatosensory input of affected side and to increase the motor function and balance ability.

• Structural Engineering and Mechanics
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• v.33 no.2
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• pp.159-177
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• 2009

The aim of this paper is to give a rigorous framework for the interpretation of limit analysis results including large displacements. The presentation is oriented towards unidimensional media (beams) but two-dimensional (plates) or three-dimensional media are also concerned. A single-degree-of-freedom system is first considered: it shows the basic phenomena of large displacement limit analysis or second-order limit analysis. The results are compared to those of a continuous system and the differences between both systems are discussed. Theoretical results are obtained using the kinematical approach of limit analysis. An admissible load-displacement plane is then defined, according to the yield design theory. The methodology used is applied to frame structures. The presented results are nevertheless different from those already published in the literature, as the virtual displacement field can be distinguished from the displacement field at collapse. The simplicity of large displacement limit analysis makes it attractive for practical engineering applications. The load-displacement upper bound can be used for instance in the optimal design of steel frames in seismic areas.

• Journal of the Chungcheong Mathematical Society
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• v.5 no.1
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• pp.65-74
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• 1992

In this note, we show that the ${\omega}$-limit mapping is continuous and the Lipschitz constants vary continuously if the flow (x, ${\pi}$) is Lipschitz stable. Moreover we analyse the ${\omega}$-limit sets under the generalized locally Lipschitz stable flows.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.348-352
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• 2018

BioRescue ($RMIng{\acute{e}}nierie$, Marseille, France) is able to assess dynamic and static balance when a test subject stands or sits over the platform. Although previous studies have examined the reliability of other balance measurement methods, little research has been conducted on the reliability of equipment such as BioRescue. This study examined the intra-rater and inter-rater reliability of BioRescue during balance assessment. Thirty-four healthy adults participated as subjects and two physical therapists participated as examiners to determine intra- and inter-rater reliability. BioRescue was used to conduct measurements during footprint (area and pressure), Romberg, and limit of stability tests. The footprint area and limit of stability tests yielded intra- and inter-rater reliability ICC values above 0.60 in all directions. However, the footprint pressure and Romberg tests yielded values below 0.60 in all directions. BioRescue showed good inter-rater and intra-rater reliability in measurements during footprint area and limit of stability tests. However, because the values of limits of stability show the difference between experienced and unskilled, skill is required for the accuracy of the equipment.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.117-127
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• 2007

Slope stability analysis is a geotechnical engineering problem characterized by many sources of uncertainty. Some of them are connected to the uncertainties of soil properties involved in the analysis. In this paper, a numerical procedure for integrating commercial finite difference method into probabilistic analysis of slope stability is presented. Since the limit-state function cannot be expressed in an explicit form, the ANN-based response surface method is adopted to approximate the limit-state function and the first-, second-order reliability method and the Monte Carlo simulation technique are used to calculate the probability of failure. Probabilistic stability assessments for a hypothetical two-layer slope and the Sugar Creek embankment were performed to verify the application potential to the slope stability problems. The examples show the successful implementation and the possibility of the extension of the proposed procedure to the variety of geotechnical engineering problems.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.147-148
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• 2014

This article describes an investigation of flame stability characteristics with various compositions of synthetic natural gas (SNG) in dual swirl combustor. The objective of this study is to investigate the flame stabilization, flame structure, fuel compatibility using chemiluminescence measurement in SNG with varying fuel compositions. As experimental conditions, hydrogen content was adjusted from 0 to 11%. Experimental results show that the addition of hydrogen has a major effect on flame behavior due to the higher burning rates associated with hydrogen consequently, The higher reaction activity of hydrogen has extended lean blow-off limit. Especially, DI flame limit has improved more 12.1%.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.483-490
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• 2002

This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement suggesting that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analysis were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of factor of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow rule are selected.

• Journal of the Korean Society of Combustion
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• v.18 no.2
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• pp.42-50
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• 2013

Linear stability analysis of radiating counterflow diffusion flames is numerically conducted to examine the instability characteristics of cellular patterns. Lewis number is assumed to be 0.5 to consider diffusional-thermal instability. Near kinetic limit extinction regime, growth rates of disturbances always have real eigen-values and neutral stability condition of planar disturbances perfectly falls into quasi-steady extinction. Cellular instability of disturbance with transverse direction occurs just before steady extinction. However, near radiative limit extinction regime, the eigenvalues are complex and pulsating instability of planar disturbances appears prior to steady extinction. Cellular instability occurs before the onset of planar pulsating instability, which means the extension of flammability.