• International Journal of Concrete Structures and Materials
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• v.18 no.1E
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• pp.35-41
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• 2006

It is expected that recent development of mechanical models will soon supersede previous empirical methods of detailing. In this study, a mechanical model is proposed to analyze the behavior of the anchorage zone of prestressed concrete members. The main characteristics of the proposed model lies in its rational consideration of material properties such as concrete strength in biaxial stress state and that of local zone reinforced by spirals. The shear friction strength of concrete surrounding a spiral is also considered. The computational results of the proposed model as well as the existing Strut-and-Tie model(STM) and nonlinear finite element analysis are compared with experimental results. The results of the comparison revealed that the proposed model showed better prediction of the failure mode as well as the failure load. Additionally, the proposed model also explained the three-dimensional failure mechanism very well, while other methods based on two-dimensional analysis could not do so well.

• Journal of Ocean Engineering and Technology
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• v.9 no.2
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• pp.41-52
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• 1995

the necessity of development of the Nearshore zone greatly emphasis in recent years. In the wave deformation model, we can get the wave height and wave direction using the hyperbolic mild slope equation considered the reflection wave. Radiation Stress the driving force of flow was calculated by the Watanabe and Maruyama who proposed on the partial standing wave. In the surf zone, applying the Izumiya and Horikawa's turbulent model considered the bottom friction and energy dissipation, we compared and examined with the Numerical model and Hydraulic test result of Watanabe and Maruyama. This model results obtained for Jin-ha Beach agreed well with the Numerical results. This model is expected so helpful to solve the prediction of the wave deformation problems in the development of the Nearshore zone in the future.

• Journal of Soil and Groundwater Environment
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• v.16 no.3
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• pp.17-27
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• 2011

Recently, a physically based model of water-table fluctuation due to precipitation is developed based on aquifer water balance model. In the model, it was assumed that the water infiltration into ground surface is advection dominant and immediately reaches to water-table. The assumption may be suited for the sites where the water-table is shallow and/or the permeability of the unsaturated zone is high. However, there are more cases where the model is not directly applicable due to thick and low permeable unsaturated zone. For the low permeability unsaturated zone, the pattern of water flux passing through unsaturated zone is diffusive as well as advective. In this study, to improve the previously developed water-table fluctuation model, we combined the delayed drainage model, which has long been used in well hydraulics, to the water-table fluctuation model. To test the validity of the development, we apply the developed model to 5 different domestic sites. The model parameters are calibrated based on the groundwater hydrograph and the precipitation time series, and the correlation analyses among the parameters are pursued. The overall analyses on the delineated model parameters indicate that the delayed drainage parameters or delay index used in the developed model are able to reveal drainage information in the unsaturated zones.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06a
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• pp.119-127
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• 2003

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are‘active zone’and‘passive zone’. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11b
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• pp.235-239
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• 2000

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.39-43
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• 2005

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain istribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.167-174
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• 2017

PURPOSES: This study aims to analyze the impact of the implementation of a school zone traffic safety improvement project on the number of accidents involving children in these zones. METHODS : To analyze the correlation between school zone traffic safety features of roads in the zone and the number of accidents involving children, we developed an occurrence probability model of traffic accidents involving children by using a binary logistic regression model with SPSS 23.0 software. Two separate models were developed for two zones: interior block and arterial road. RESULTS :The model depicted that in the case of the interior block, shorter sidewalk width, speed bump, and an elevated crosswalk were key factors affecting the occurrence of accidents involving children. In the case of arterial roads exceeding a width of 12 m, the speed limit, roadside barriers, and red paving of road surfaces were found to be the key factors. CONCLUSIONS:The results of this study can serve as the elementary research data to help improve the effectiveness of school zone traffic safety improvement projects and school zone road repair projects in future.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.138-144
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• 2003

A crack in a ferroelectric ceramic subjected to an electric field is analyzed. The boundary of the electrical saturation zone is estimated based on the finite-width saturation zone model, which is analogous to a finite-width Dugdale zone model for mode III. It is shown that the shape and size of the switching zone depends strongly on the boundary of the electrical saturation zone and the ratio of the coercive electric field to the yield electric field. The crack tip stress intensity factor under small scale conditions is evaluated by employing the model of electric nonlinear domain switching. It is found that fracture toughness of the ferroelectric material may be increased or decreased depending on the material property of electrical nonlinearity.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.3
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• pp.67-79
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• 2003

An efficient mobility management for mobile stations plays an important role in mobile communication networks. Even though many a mobility management schemes have been proposed, most of mobile communication networks adopt the mobility scheme based on zone-based registration. This paper studies the mobility management scheme that combines zone-based registration and 2-step selective paging. We assume cell by cell registration area, not ring by ring registration area of previous studies, and set up a new mobility model based on 2-dimensional random walk model considering the characteristic of zone-based registration to evaluate its performance exactly. We provide numerical results using proposed model to demonstrate the performance of zone-based registration and 2-step selective paging under various circumstances.

• Journal of Korea Water Resources Association
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• v.37 no.4
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• pp.257-271
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• 2004

To evaluate behavior in representing solute transport in natural streams, the storage zone model of the axially periodic transient storage zones is developed. The periodic transient storage zone model and continuous storage zone model are verified using the parameters and the tracer concentration vs. time curves observed in laboratory channels. The periodic storage zone model best fit the measured concentration vs. time curves, while the continuous storage model fails to describe some fluctuations and the plateau region of the tail occurring in a discontinuous transient storage system. Dispersion data from Shingobee River, Minnesota, U. S. A. show that the concentration curves simulated by the proposed model fit the observed concentration curves well.