• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.4
• /
• pp.545-552
• /
• 2020

This study evaluated the support performance of fiber-net integrated shotcrete in tunnel support system developed for the purpose of improving constructability and stability while fully performing its mechanical performance as a tunnel support materials by four-point bending test, two-dimensional numerical analysis, and cross-sectional analysis. As a result of evaluating the flexural performance through a four-point bending test, in the case of fiber-net reinforced shotcrete, the tensile performance of fiber-net resulted in a continuous increase in load after crack occurrence, unlike steel fiber reinforced shotcrete. Also, the results of the tunnel cross-sectional structure analysis for ground conditions and the cross-sectional analysis of fiber-net and steel fiber reinforced shotcrete showed that sufficient support performance can be exhibited even if the thickness of fiber-net reinforced shotcrete was reduced compared to the previous one. Additionally, through these results, the support pattern of fiber-net integrated shotcrete in tunnel support system, which can be applied efficiently to the construction sections requiring higher stability among the rock mass class III, was proposed.

• Tunnel and Underground Space
• /
• v.7 no.3
• /
• pp.191-201
• /
• 1997

Geological and geotechnical surveys, in general, should precede the excavation to ensure the safety of the tunnel and should be followed up according to the various geological condition during the excavation. However actually the standard support patterns which were decided during the design step used be insisted for the whole excavation steps in spite of the various geological conditions. OO tunnel was excavated with NATM and a support pattern type-V in weak rocks. When the tunnel was excavated up to 25m long, the severe displacement was generated in the portal area and the shotcrete was damaged to make the cracks and the tunnel face was totally collapsed. It might happen owing to the one-day heavy rain, but the exact reason for that accident should be found out and the new optimal support patternt needed. Consequently three dimensional numerical analysis was applied for the evaluation of the cause of the tunnel collapse instead of two dimensional analysis, because three dimensional analysis can show better the real field phenomenon than two dimensional analysis in which the load distribution methods are adopted for the tunnel excavation. We could simulate the actual situations with three dimensional finite difference code and propose the new optimal support patterns.

• Journal of Korea Multimedia Society
• /
• v.15 no.6
• /
• pp.701-710
• /
• 2012

Retinitis Pigmentosa(RP) is a common hereditary disease. While they have been normally living, those who have this symptom feel frustration and pain by the damage of visual acuity. At the national level, the loss of the economic activity due to the reduction of economically active population will be also greater. There is an urgent need for the base study that can provide the clinical prognosis information of RP disease. In this study, we suggest that it is possible to predict prognosis through the pattern classification of RP data. Statistical processing results through statistical software like SPSS(Statistical Package for the Social Service) were mainly applied for the conventional study in data analysis. However, machine learning and automatic pattern classification was applied to this study. SVM(Support Vector Machine) and other various pattern classifiers were used for it. The proposed method confirmed the possibility of prognostic prediction based on the result of automatically classified RP data by SVM classifier.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.320-322
• /
• 2009

Support vector learning attracts great interests in the areas of pattern classification, function approximation, and abnormality detection. In this pater, we design the controller using support vector regression which has good properties in comparison with multi-layer perceptron or radial basis function. The applicability of the presented method is illustrated via an example simulation.

• Journal of the Semiconductor & Display Technology
• /
• v.8 no.3
• /
• pp.39-44
• /
• 2009

Local Binary Pattern (LBP) is becoming a popular tool for various machine vision applications such as face recognition, classification and background subtraction. In this paper, we propose a new extension of LBP, called the Diagonal LBP (DLBP), to handle the image-based gender classification problem arise in interactive display systems. Instead of comparing neighbor pixels with the center pixel, DLBP generates codes by comparing a neighbor pixel with the diagonal pixel (the neighbor pixel in the opposite side). It can reduce by half the code length of LBP and consequently, can improve the computation complexity. The Support Vector Machine is utilized as the gender classifier, and the texture profile based on DLBP is adopted as the feature vector. Experimental results revealed that our approach based on the diagonal LPB is very efficient and can be utilized in various real-time pattern classification applications.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.15 no.4
• /
• pp.268-276
• /
• 2015

A ship's sailing route or plan is determined by the master as the decision maker of the vessel, and depends on the characteristics of the navigational environment and the conditions of the ship. The trajectory, which appears as a result of the ship's navigation, is monitored and stored by a Vessel Traffic Service center, and is used for an analysis of the ship's navigational pattern and risk assessment within a particular area. However, such an analysis is performed in the same manner, despite the different navigational environments between coastal areas and the harbor limits. The navigational environment within the harbor limits changes rapidly owing to construction of the port facilities, dredging operations, and so on. In this study, a support vector machine was used for processing and modeling the trajectory data. A K-fold cross-validation and a grid search were used for selecting the optimal parameters. A complicated traffic route similar to the circumstances of the harbor limits was constructed for a validation of the model. A group of vessels was composed, each vessel of which was given various speed and course changes along a specified route. As a result of the machine learning, the optimal route and voyage data model were obtained. Finally, the model was presented to Vessel Traffic Service operators to detect any anomalous vessel behaviors. Using the proposed data modeling method, we intend to support the decision-making of Vessel Traffic Service operators in terms of navigational patterns and their characteristics.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.1
• /
• pp.211-224
• /
• 2018

It is important to design tunnel support system considering the various loads acting on the tunnel because they have a direct impact on the stability of tunnels. In Korea, standardized support patterns are defined based on the rock mass classification system depending on the project, and it is stated that it should be modified appropriately considering the behavior of tunnel during construction. In this study, the tunnel support pattern optimization method is suggested based on the convergence-confinement method, earth pressure, axial force of rock bolt, and moment acting on the shotcrete. The length and spacing of the rock bolts and the thickness of the shotcrete were optimized by using the differential evolution algorithm (DEA) and the results were compared to the standard support pattern III for railway tunnel. Rock bolt length can be reduced and the installation interval can be widened for shallow tunnel. As the depth of tunnel increases, the thickness of shotcrete increases linearly. Therefore, the thickness of shotcrete should be thicker than the standard support pattern as the depth of tunnel increases to secure the stability of tunnel.

• Journal of Haehwa Medicine
• /
• v.23 no.1
• /
• pp.125-135
• /
• 2014

Objectives : The purpose of this study is to detect the change of pattern according to phase and to identify the associated factors with depression in stroke patients. Methods : The study was designed as a longitudinal study. Data was collected from 90 subjects, who were diagnosed with stroke using a brain MRI. The instruments included rehabilitation will, social support, FIM(Functional Independence Measure), NIHSS(National Institute of Health Stroke Scale), and BDI(Beck Depression Index). The collected data were analyzed using by SPSS 19.0 program package. Results : There were significant differences of depression pattern among the three phases. The most depression associated factor was the level of FIM. Conclusion : These results will support strategies for intervention to improve depression of stroke patients. Most affecting factors should be considered for depression intervention.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.925-930
• /
• 2006

During the excavation of a tunnel portal, failure zones around the tunnel heading occur and also the ground supports itself. In a portal, its location and the ground characteristic have a great influence on the stability of the tunnel. Therefore, the failure mechanism of a tunnel heading and how to assess the stability of the tunnel are very important. In this paper, the numerical analyses were executed to evaluate the safety factor using strength reduction technique. The influence area of an excavation was also predicted through a case study in which no-support case and support case with the Pattern P-6 were compared in terms of the ground class and the shear strain.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.3 no.4
• /
• pp.17-24
• /
• 2001

Four road tunnels of which the construction conditions were similar were selected in the paper, and laboratory tests and rockmass classification for the tunnels were carried out. And the analysis was performed to find out the correlation between ratio of bit abrasion or drilling parameter and support pattern of tunnel using jumbo drill machine. It was analyzed that there was average abrasion of bit from 11.85% to 3.25% per support patterns of tunnel in four tunnels. Drilling parameter happens to fluctuate according to extent of fracture zone.