• Journal of the Korean Geosynthetics Society
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• v.10 no.2
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• pp.1-12
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• 2011

In order to analyze the influence of particle bonding and crushing on the characteristics of shear behavior, especially residual shear behavior of granular soil, ring shear test was simulated by using DEM(Discrete Element Method)-based software program PFC(Particle Flow Code). Total four models including two non-crushing models and two crushing models were created in this study by using clump or cluster model built in PFC. The applicability of Lobo-crushing model proposed by Lobo-Guerrero and Vallejo(2005) was investigated. In addition, the results of ring shear test were analyzed and compared with those of direct shear test. The results showed that the modelling of ring shear test should be conducted to investigate the residual shear behavior. The Lobo-crushing model cannot be applied to investigate the residual shear strength. Finally, it can be concluded that the numerical models excluding Lobo-crushing model suggested in this study can be used extensively for other studies concerning the residual shear behavior of granular soil including soil crushing.

• Journal of KIISE
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• v.44 no.11
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• pp.1178-1193
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• 2017

It is very important to understand system behaviors in collective pattern for each knowledge domain. However, there are structural limitations to represent collective behaviors because of the size of system components and the complexity of their interactions, causing the state explosion problem. Further composition with other systems is mostly impractical because of exponential growth of their size and complexity. This paper presents a practical method to model the collective behaviors, based on a new concept of domain engineering: behavior ontology. Firstly, the ontology defines each collective behavior of a system from active ontology. Secondly, the behaviors are formed in a quantifiably abstract lattice, called common regular expression. Thirdly, a lattice can be composed with other lattices based on quantifiably common elements. The method can be one of the most innovative approaches in representing system behaviors in collective pattern, as well as in minimization of system states to reduce system complexity. For implementation, a prototype tool, called PRISM, has been developed on ADOxx Meta-Modelling Platform.

• Explosives and Blasting
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• v.37 no.4
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• pp.26-35
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• 2019

In designing a gravity-type anchorage of earth-anchored suspension bridge, the contact friction between a blasted rock mass and the concrete anchorage plays a key role in the stability of the entire anchorage. Therefore, it is vital to understand the shear behavior of the interface between the blasted rock mass and concrete. In this study, a portable 3D LiDAR scanner was utilized to scan the blasted bottom surfaces, and rock surface roughness was quantitatively analyzed from the scanned profiles to apply to 3D FEM modelling. In addition, based on the 3D FEM model, a three-dimensional dynamic fracture process analysis (DFPA-3D) technique was applied to study on the shear behavior of the interface between blasted rock and concrete through direct shear tests, which was analyzed under constant normal load (CNL). The effects of normal stress and the joint roughness on shear failure behavior are also analyzed.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.284-292
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• 2024

Purpose: Compared to general fires of the same size, underground parking lot fires are more likely to cause human and property damage and are not easy for firefighters to extinguish fire and save lives. This study attempted to find out how to secure the evacuation safety of parking lot users based on changes in the evacuation simulation behavior mode applied to evaluate the evacuation safety of the object. Method: Simulation for each CASE was performed using the Pathfinder program. Result: it was found that the higher the reference value, the higher the evacuation time, and Behavior showed an increase in time in SFPE mode rather than Steering mode. Priority was able to confirm an increase in time in priority designation rather than non-priority designation. Conclusion: The Required Safe Egress Time (RSET) for evaluating the evacuation safety of underground parking lots and the building evacuation design to ensure evacuation safety should be evaluated and reflected separately from Simulation's Behaviour Mode and Priority.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.812-826
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• 2012

The selection rate of tree burials (TB) is still low in spite of increasing concerns about TB and government's efforts to increase TB participation. It is necessary to understand the factors affecting TB selection. This study investigated the relationship between major variables (attitude: ATT; subjective norm: SN; perceived behavioral control: PBC) of Ajzen's theory of planned behavior (TPB), additional variable (custom: CUST), and intention to select TB by using structural equation modelling (SEM). Samples were selected from Gwang-ju citizens using proportionate stratified sampling (PST) by region during September of 2011. Four hundred and twelve responses were used for data analysis. The model showed fair goodness of fit. All four variables (ATT, SN, PBC, CUST) influenced intention to select TB. The four variables explained 53.0% of intention to select TB. SN(${\beta}$=0.459) was the most predictive variable on the intention, followed by ATT(${\beta}$=0.247), PBC(${\beta}$=0.152), and CUST(${\beta}$=0.102) in decreasing order. The results were discussed and some suggestions to increase the intention of tree burial selection were made.

• Steel and Composite Structures
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• v.21 no.2
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• pp.411-427
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• 2016

While the cyclic behaviour of fiber-reinforced polymer (FRP)-confined columns is studied rather extensively, the cyclic response especially the energy dissipation of FRP-confined damaged and undamaged square RC columns is not yet fully understood. In this paper, an experimental and numerical investigation was conducted to study the cyclic behavior of two different types of Carbon FRP (CFRP)-confined square RC columns: strengthened and repaired. The main variables investigated are initial damage, confinement of CFRP, longitudinal steel reinforcement ratio. The experimental results show that lower initial damage, added confinement with CFRP and longitudinal reinforcement enhance the ductility, energy dissipation capacity and strength of the columns, decrease the stiffness and strength degradation rates of all CFRP-confined square RC columns. Two hysteretic constitutive models were developed for confined damaged and undamaged concrete and cast into the non-linear beam-column fiber-based models in the software Open System for Earthquake Engineering Simulation (OpenSees) to analyze the cyclic behavior of CFRP-confined damaged and undamaged columns. The results of the numerical models are in good agreement with the experiments.

• Composites Research
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• v.13 no.1
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• pp.25-32
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• 2000

In this paper, postbuckling behavior of laminated composite-stringer stiffened-curved panels loaded in local compression is analyzed using the finite element program developed. Postbuckling Analysis is performed in dividing the panel behavior into three basic parts. The eight node degenerated shell element is used in modelling both panel and stiffeners, and the updated Lagrangian description method based on the 2nd Piola-Kirchhoff stress tensor and the Green strain tensor is used for the nonlinear finite element formulation. The progressive failure analysis is adopted in order to grasp the failure characteristics. The postbuckling experiment of the laminated composite-stiffened-curved panel had been done to verify the finite element analysis. The buckling load and the postbuckling ultimate load are compared in parametric study.

• Steel and Composite Structures
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• v.8 no.3
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• pp.179-200
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• 2008

This paper reports the results of a recent experimental study into the behavior of welded fin-plate connections to both hollow and concrete filled tubular (CFT) columns under shear. Experiments have been performed at both ambient and elevated temperatures with the aid of an electric kiln. The observed failure modes include fracture of the fin plate and tearing out of the tube around the welds. By considering the results of previously published research, the current design method for similar connections under purely tensile load, in CIDECT Guide 9, based on a deformation limit of 3% of the tube width is shown to be inadequate when evaluating the ultimate strength of such connections. By comparing the results from the current test program which failed in the fin-plate with Eurocode guidance for failure of a fin-plate alone under shear and bending load it is shown that the column face influences the overall connection strength regardless of failure mode. Concrete in-fill is observed to significantly increase the strength of connections over empty specimens, and circular column specimens were observed to exhibit greater strength than similarly proportioned square columns. A finite element (F.E.) model, developed using ABAQUS, is presented and validated against the experimental results in order that extensive parametric tests may be subsequently performed. When validating the model against elevated temperature tests it was found that using reduction factors suggested in published research for the specific steel grades improved results over applying the generic Eurocode elevated temperature steel strength reduction factors.

• Knowledge Management Research
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• v.13 no.5
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• pp.91-111
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• 2012

The purpose of this study is to investigate the effect of person-organization fit(PO fit) and person-job fit(PJ fit) on positive psychological capital at both team-level and individual-level. Present study intends to confirm the effectiveness through theoretical considerations and empirical analysis of positive organizational behaviors. This is expected to strengthen the basis of positive organizational behavior studies and provide the foundation to integrate positive organizational behavior to the actual organization. In order to test the hypotheses, the data were collected from multiple domestic organizations and composed 47 team-level and 244 individual-level data. For the analysis, hierarchical linear modelling(HLM) were conducted. The results of this study are as follows. PO fit and PJ fit had significant relationships with positive psychological capital at both team-level and individual-level. Also, in the relationship between the attitudes and behaviors of the members and positive psychological capital, the positive psychological capital was found to have significant effect on affective commitment and organizational citizen behaviors. The implications of this study according to the results as follows. Positive relationships of psychological capital with the antecedents and consequences variables, it is necessary for the management to magnify the strength of members in the actual operation at the organization level. Such the management of positive psychological capital can be suggested as a new approach method for achievement of the organization's goals and visions.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.5
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• pp.705-712
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• 2012

Selecting Daechung Dam as a sample study site, this study simulates virtual water quality incident which can be occurred using EFDC maintained by USEPA. In order to predict the behavior and diffusion of leaked conservative pollutant within dam under the worst condition, the hydrological data and information from 2008 were used. EFDC was successfully calibrated for observed water level obtained from the above sources. From the results of simulations, even though the concentrations (500 ppm, 1,000 ppm and 10,000 ppm) of leaked pollutant were different with each other at the same sources, the travel time of each peak concentration appeared similar. Also, changing the leak source point from dam gate(0 km) to 7 km, it was found that as leak source point was nearer to the dam gate, the travel time of each peak concentration showed up sooner. It was simulated to take 1 day to 15 days for initial appearance of the leaked pollutant according to the leaked points, and 3 days to 25 days for the reach of the peak concentration, respectively.