• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.92-101
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• 2007

Urban freight system includes not just intra-urban freight movement but also inter-urban movement as well. Hence, to make Busan a hub of North-east asia freight movement it is necessary to develop a comprehensive plan for infrastructure expansion as well as improvement of freight system based on the present facility situation. This study identifies the status of freight facilities in Busan by establishing the freight related infrastructure Database(DB) utilizing Geographic Information System(GIS), and to enable planners and decision-makers to utilize the DB to develop a future plan. The DB includes port facilities, major and minor arterial roads, railroad lines and facilities, depots, center city business areas, and urban infrastructures which are related to the freight movements. The analyses show that major transportation facilities in Busan consist of roads, railroads, coastal transportation, and international transportation, and it was found that intermodal facilities are inadequate for freight system in Busan. The results of this study will be useful for freight experts and planners to develop a comprehensive freight system plan.

• Journal of Korean Tunnelling and Underground Space Association
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• v.18 no.5
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• pp.431-439
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• 2016

This paper dealt with contents of the quality evaluation method of lattice girder utilizing non-destructive method. Quality evaluation of ordinary lattice girder is performed through the tensile strength test of structural steel and visual inspection. The tensile strength test of structural steel is performed by collecting samples of lattice girder brought into the site, during which lattice girder must be damaged to obtain sample. In addition to such disadvantage, tensile strength tester is not available at the site in most cases, requiring an inconvenient service from test certification agency. In addition, it is substituted by mile sheet issued during the production of structural steel, which inevitably lacks reliability. Furthermore, visual inspection at the site entails a problem of lack of reliability, thereby requiring a method of easily and quickly evaluating the quality of lattice girder without damaging the material. Accordingly, this study comparatively analyzed the yield strength of tensile strength test and the yield strength of instrumented indentation test with same sample. The test results ensured over 95% precision level for the instrumented indentation test, based on which a quality evaluation method based on instrumented indentation test that allowed onsite direct quality evaluation is proposed.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1982-1990
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• 2010

Excepting tunnel of dorimstream - ccachimountain station section, the subway line No.2th section was build using ASSM and NATM methods because of soil pressure and land condition. The way of dealing underground water was selected without sufficient preconsideration of geographical features, ground condition, influence of lowing underground water, and long-term cost of running maintenance so that the form of undrained tunnel was build having decreased construction characteristics and technically improper elements. The form of partial drainage is very difficult to manage structures of tunnel, because water leakage, water pressure causing cracks of lining concretes and scaling are constantly happened. so partial drainage suggest that setting reinforced Anchor Bolt to prevent buoyancy and should increase center drainage way up to height of railroad. Partial drainage suggest that holey pipe(${\phi}$350mm) manhole, drainage checking pipe manhole are should be regularly dredged, when changing roadbed(gravel${\rightarrow}$concrete) drainage checking pipe manhole should be build and setting a limitation of entering underground water's quantities. Beside drainage degree in changed section of structures causing instability of structures is continuous degree. so if efficient drainage way and the patterns of flaws, problems are considered in survey, it will be expected to have a advantage condition in maintenance part.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.441-450
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• 2006

The on-land seismic survey in Korea was begun in mid-1960s. Kim et al.(1967) of Korea Geological Survey reported on the result of gravity and seismic reflection surveys conducted in the Pohang area for the period of 1963-64 to assess its possibility of oil entrapment. Hyun and Kim (1966) carried out a refraction survey on the tunnel wall. Since then, the KGS geophysicists had conducted seismic surveys on Kyungsang sedimentary basin as a main project for several years. In 1970s, on-land seismic surveys had been conducted for various purposes such as site investigation for the nuclear power plants and industrial complex, exploration for ground water, mineral resources and underground tunnel. The first reflection survey with CMP acquisition was attempted in 1978 by using a digital recording system. But most of on-land seismic surveys had employed the refraction method until 1980s. In 1990s, high resolution reflection and various borehole seismic surveys such as tomography, uphole, downhole, cross-hole methods have been attempted by universities and engineering companies. The applications of on-land seismic surveys have been enlarged for both academic and industrial purposes such as investigation of geologic structure of the fault and tidal flat area, construction of highway, railroad and dam, geothermal energy and mineral resource exploration, environmental assessment for waste disposal sites and archaeological investigations. In 2002, the first crustal seismic survey was carried out on the profile of 294km length across the whole peninsular. It is expected that the advanced technology and experience acquired through offshore seismic surveys, which have been conducted in continental shelf of Korea and foreign oil fields, will stimulate the more active on-land seismic explorations.

• The Journal of Engineering Geology
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• v.5 no.1
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• pp.1-20
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• 1995

A train overturn accident occurred on March 1993 in the Gupo area, northern part of Pusan, unfortunately had taken a heavy toll of lives and caused a great loss of property as well. The reasons for the subsidence of the basement under the railroads, which presumed to be the main cause of the accident, have been investigated from many different angles, including conventional geotechnical investigation methods. The deduced nuin reasons of the subsidence were: 1. blasting for tunnel excavation (NATM) at about 39 meter under the railroads, and 2. unexpected change of bedrock conditions along the direction of tunnel. But this accident was derived nrranlv from the lack of geological and geotechnical information under railroad area because it was impossible to drill beneath the railroads. This paper introduces a new geophysical survey techniqueseisrnic geotomography, and shows some results of the method applying to investigate the underground structure of the accident area. This method not only overcomes the unfavourable environment which many conventional investigation methods cannot face, but produces an image of underground structure with high resolution. Furthermore, the outputs from geotomogaphic analysis could provide very valuable in-situ basic parameters (like seismic velocities, elastic moduli, etc.) which is essential to the design and construction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.405-413
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• 2017

In this paper, we study the biaxial buckling analysis of nonlocal MEE(magneto-electro-elastic) nano plates based on the first-order shear deformation theory. The in-plane electric and magnetic fields can be ignored for MEE(magneto-electro-elastic) nano plates. According to magneto-electric boundary condition and Maxwell equation, the variation of magnetic and electric potentials along the thickness direction of the MME plate is determined. In order to reformulate the elastic theory of MEE(magneto-electro-elastic) nano-plate, the nonlocal differential constitutive relations of Eringen is used. Using the variational principle, the governing equations of the nonlocal theory are discussed. The relations between nonlocal and local theories are investigated by computational results. Also, the effects of nonlocal parameters, in-plane load directions, and aspect ratio on structural responses are studied. Computational results show the effects of the electric and magnetic potentials. These computational results can be useful in the design and analysis of advanced structures constructed from MEE(magneto-electro-elastic) materials and may be the benchmark test for the future study.

• Journal of Korea Water Resources Association
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• v.53 no.6
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• pp.395-408
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• 2020

This paper aims to develop and apply three different machine learning approaches (i.e., artificial neural networks (ANN), adaptive neuro-fuzzy inference systems (ANFIS), and wavelet-based neural networks (WNN)) combined with an evolutionary optimization algorithm and the k-fold cross validation for multi-step (days) streamflow forecasting at the catchment located in Algeria, North Africa. The ANN and ANFIS models yielded similar performances, based on four different statistical indices (i.e., root mean squared error (RMSE), Nash-Sutcliffe efficiency (NSE), correlation coefficient (R), and peak flow criteria (PFC)) for training and testing phases. The values of RMSE and PFC for the WNN model (e.g., RMSE = 8.590 ㎥/sec, PFC = 0.252 for (t+1) day, testing phase) were lower than those of ANN (e.g., RMSE = 19.120 ㎥/sec, PFC = 0.446 for (t+1) day, testing phase) and ANFIS (e.g., RMSE = 18.520 ㎥/sec, PFC = 0.444 for (t+1) day, testing phase) models, while the values of NSE and R for WNN model were higher than those of ANNs and ANFIS models. Therefore, the new approach can be a robust tool for multi-step (days) streamflow forecasting in the Seybous River, Algeria.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.775-784
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• 2009

Weathered foliation could act as a critical failure plane because this type of plane tend to have low roughness and long extensions. A big constructed slope at $\bigcirc\bigcirc$ road construction site was failed due to the block movement along a fault zone which is parallel to foliation. Tectonic activity reactivated a fault zone parallel to foliation, and the fault clay within the shear zone metamorphosed retrogressively to chrolite. The failed block moved when the block weigh lost the balancing with the resisting force of the retrogressively metamorphosed chrolite. Evaluating the three dimensional distribution of the foliation was critical for establishing a plan for the stabilization of the slope. For this purpose, 10 boreholes were drilled as a lattice distribution, and the BIPS analyses are performed at each boreholes. The fractures measured in the boreholes are projected into 15 cross sections and their distributions are analysed, using Fracjection software. The projection analyse show that the strike of the foliation gets dipper towards left side of the slope. This geometry indicates that there are more failure block geometry at left side of the slope. Potential failure planes are searched using the projection method, and these information are provided for further support design.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.6
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• pp.529-538
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• 2016

The simplified plate theory is presented for static and free vibration analysis of power-law(P) and sigmoid(S) Functionally Graded Materials(FGM) plates. This theory considers the parabolic distribution of the transverse shear stress, and satisfies the condition that requires the transverse shear stress to be zero on the upper and lower surfaces of the plate, without the shear correction factor. The simplified plate theory uses only four unknown variables and shares strong similarities with classical plate theory(CPT) in many aspects such as stress-resultant expressions, equation of motion and boundary conditions. The material properties of the plate are assumed to vary according to the power-law and sigmoid distributions of the volume fractions of the constituents. The Hamilton's principle is used to derive the equations of motion and Winkler-Pasternak elastic foundation model is employed. The results of static and dynamic responses for a simply supported FGM plate are calculated and a comparative analysis is carried out. The results of the comparative analysis with the solutions of references show relevant and accurate results for static and free vibration problems of FGM plates. Analytical solutions for the static and free vibration problems are presented so as to reveal the effects of the power law index, elastic foundation parameter, and side-to-thickness ratio.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.553-561
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• 2015

The exponential and power law functionally graded material(FGM) theory is reformulated considering the refined shear and normal deformation theory. This theory has ability to capture the both normal deformation effect and exponential and power law function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported plates on Pasternak elastic foundation. Numerical solutions of vibration analysis of FGM plates are presented using this theory to illustrate the effects of power law index and 3-D theory of exponential and power law function on natural frequency. The relations between 3-D and 2-D higher-order shear deformation theory are discussed by numerical results. Further, effects of (i) power law index, (ii) side-to-thickness ratio, and (iii) elastic foundation parameter on nondimensional natural frequency are studied. To validate the present solutions, the reference solutions are discussed.