• Geomechanics and Engineering
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• v.15 no.3
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• pp.911-917
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• 2018

This paper concerns a numerical investigation on the effect of construction sequence on three-arch (3-Arch) tunnel behavior. A three-arch tunnel section adopted in a railway tunnel construction site was considered in this study. A calibrated 3D finite element model was used to conduct a parametric study on a variety of construction scenarios. The results of analyses were examined in terms of tunnel and ground surface settlements, shotcrete lining stresses, loads and stresses developed in center column in relation to the tunnel construction sequence. In particular, the effect of the side tunnel construction sequence on the structural performance of the center structure was fully examined. The results indicated that the load, thus stress, in the center structure can be smaller when excavating two side tunnels from opposite direction than excavating in the same direction. Also revealed was that no face lagging distance between the two side tunnels impose less ground load to the center structure. Fundamental governing mechanism of three-arch tunnel behavior is also discussed based on the results.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.473-480
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• 1999

This paper presents the results of a parametric study on the behavior of mechanically stabilized earth retaining wall. It has been recognized that the currently available design guidelines, which is base on the limit equilibrium approach, cannot properly account the interaction effect between the components, construction sequence, and foundation settlement which may impose a significant influence on the wall behavior. A parametric study using finite element analysis was performed to investigate the behavior of MSE wall under different construction conditions and the applicability of the current design approach. In the parametric analysis, the effects of the construction sequence, the surcharge, and the foundation stiffness were studied and a detailed finite element modeling for various components of the system were employed. The results, such as wall displacement and earth pressure distributions, reinforcement forces, vertical stress distribution were then thoroughly analyzed to investigate the effect of construction details on the wall behavior.

• The Journal of the Korea Contents Association
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• v.8 no.9
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• pp.19-26
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• 2008

With the development of ubiquitous computing and the construction of infrastructure for one-to-one personalized services, the importance of context-aware services based on user's situation and environment is being spotlighted. The smart home technology connects real space and virtual space, and converts situations in reality into information in a virtual space, and provides user-oriented intelligent services using this information. In this paper, we proposed the discovery of the behavior sequence pattern using the mining in the smart home. We discovered the behavior sequence pattern by using mining to add time variation to the association rule between locations that occur in location transactions. We can predict the path or behavior of user according to the recognized time sequence and provide services accordingly. To evaluate the performance of behavior consequence pattern using mining, we conducted sample t-tests so as to verify usefulness. This evaluation found that the difference of satisfaction by service was statistically meaningful, and showed high satisfaction.

• International Journal of Control, Automation, and Systems
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• v.1 no.1
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• pp.111-118
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• 2003

This paper proposes a two dimensional behavior analysis method for fish in a water tank based on the ARX method and the Kalman filter algorithm using image processing technology. In modeling the behavior of fish, the input is denoted as the environmental change and uses M-sequence. The output is expressed by the partnership between fish. The behavior model of individual fish is identified by the ARX method. It is then estimated by the Kalman filter algorithm. Finally, the fish behavior is analyzed by FFT. To prove the effectiveness of the pro-posed algorithm, it is applied to two tilapias in a water tank with dimensions of 100cm$\times$100cm$\times$50cm. The effectiveness of the proposed method is demonstrated through ARX identification, estimation of Kalman filter, and FFT analysis.

• Honam Mathematical Journal
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• v.39 no.4
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• pp.665-675
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• 2017

Several properties of the sequence generated from a kind of Danzer matrices were examined and proved using already known facts about the Chebyshev polynomials. Asymptotic behavior of our interest sequence also discussed.

• KCI Concrete Journal
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• v.11 no.3
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• pp.141-151
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• 1999

In the replacement of bearing system of bridges, the jacking work to secure work spaces may cause damage of the superstructure, hence the behavior of superstructure by the jacking force must be considered. Especially, in prestressed concrete I-type girder bridges, considering the stress concentration at the girder and the load redistribution of superstructure, the allowable jacking force and jacking sequence have to be determined. In this study, an analytical method is proposed to calculate the jacking force and overall jacking sequence for the replacement of bearing system without any damage to the superstructure. The stress concentration at the girder and load redistribution of the deck due to jacking force are considered to compute the allowable jacking force for each girder and overall jacking sequence for girders in the deck. Using the solution algorithm developed in this study, the optimum jacking sequence and required jacking force for the prestressed concrete I-type gilder bridge having the standard sections are calculated.

• Journal of Korea Foundry Society
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• v.30 no.3
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• pp.100-110
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• 2010

The solidification sequence and formation of intermetallic phase of Fe-rich Al-Si-Cu alloy were investigated by using real-time imaging of synchrotron X-ray radiation. Effects of cooling rate during uni-directional solidification on the resultant solidification behavior was also studied in a specially constructed vacuum chamber in the SPring-8 facility. The series of radiographic images were complementarily analyzed with conventional analysis of OM and SEM/EDX for phase identification. Detailed solidification sequence and formation mechanisms of various phases were discussed based on real-time image analysis. The growth rates of $\alpha$-AlFeMnSi and ${\beta}-Al_5FeSi$ were measured in order to understand the growth behavior of each phase. It is suggested that real-time imaging technique can be a powerful tool for the precise understanding of solidification behavior of various industrial materials.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.357-364
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• 1998

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.201-209
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• 2023

Recently, fiber-reinforced composites have been widely used in various industrials fields. In this study, the mechanical behavior, especially fracture behavior, of biomimetic fiber-reinforced composites subjected to pressure loading was analyzed using finite element analysis (FEA). The fiber alignments in the biomimetic composites formed a helicoidal structure, wherein a stacking sequence involved a gradual rotation of each ply in the multi-layered laminated composites. For comparison, cross-ply composite samples with fibers arranged at 0° and 90° were prepared and analyzed. In addition, the mechanical behavior was analyzed based on combinations of the stacking sequence of carbon-fiber composites and glass-fiber composites. The FEA results showed that, when compared with the cross-ply samples, the mechanical properties of the biomimetic composites were considerably improved under pressure loading, which was applied to one side of the composites. Thus, the biomimetic helicoidal structure significantly improved the mechanical properties of the composites. Placing materials having high elasticity and strength in the outermost layers (the layer of the side on which pressure was applied and the opposite side layer) of the composites also significantly contributed to improving the mechanical properties of the composites.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.1
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• pp.115-122
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• 2006

The most methods for intrusion detection are based on the misuse detection which accumulates hewn intrusion information and makes a decision of an attack against any behavior data. However it is very difficult to detect a new or modified aoack with only the collected patterns of attack behaviors. Therefore, if considering that the method of anomaly behavior detection actually has a high false detection rate, a new approach is required for very huge intrusion patterns based on sequence. The approach can improve a possibility for intrusion detection of known attacks as well as modified and unknown attacks in addition to the similarity measurement of intrusion patterns. This paper proposes a method which applies the multiple sequence alignments technique to the similarity matching of the sequence based intrusion patterns. It enables the statistical analysis of sequence patterns and can be implemented easily. Also, the method reduces the number of detection alerts and false detection for attacks according to the changes of a sequence size.