• Journal of the Korean Geographical Society
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• v.31 no.4
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• pp.662-671
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• 1996

Since the world's economic and political structures have changed, the term 'globlization' has shown up as a dominant power and as a necessity for regional and national development. Each nation is responding to the globalization process economically and politically in various ways. In general, however, the economic response to the globalization is economic restructuring from the Fordist industries to 'flexible specialization'. And the political response to the globalization is 'global localization' as a new type of local politics(i.e., local policy activism or growth-enhancing local development policies). The crisis of Fordism shifted the role of local governments towards more involovement with local economic development. Local governments are mobilizing for loca economic development, they are taken into a process of institutional change that tends to redefine their responsibilities inside the state. Local governments thus tend to act as an entrepreneur in order to restructure theiir local economies and to compete with other national and international regions. State restructuring towards enerepreneurialism and efficient regional policy pursuing a pro-growth coalition trategy is chosen as a new mode of regulation for the post-Fordism at the local level. The flexible specialization as the post-Fordist economy and the local government as an entrepreneur are the global choice for globalization and a post-Fordist society. The paper focuses on the regulation theory which comprises the political economic perspective on resturcturing. Economic restructuring and state restructuring will be discussed in detail. And the paper tries to combine the economic globalization and the global localization as economic and political responses to globalization.

• Journal of the Mineralogical Society of Korea
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• v.15 no.3
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• pp.221-230
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• 2002

Weathering of biotite shows a biotite-vermiculite-kaolinite sequence at the early stage, but presents biotite-kaolinite sequence without a significant intermediate phase (vermiculite) at the late stage from the weathering profile of the granitic gneiss. Secondary 1:1 phyllosilicates are kaolinite and halloysite which show different weathering textures originated by a different formation mechanism. Kaolinitization began from the edges of biotite and propagated toward the interior of grain along a multilayered front. $10 \AA$ layers of biotite are interleaving with $7\AA$ layers of kaolinite and c-axis of two phases is consistent. Kaolinite pseudomorph of biotite is isovolumetric, compared to the biotite boundary and includes many band-like porosities parallel to the cleavage. Platy kaolinite formed by 1:1 layer fur layer replacement of biotite. Halloysitization proceeded outward from the grain edges which were foliated as fine flakes and bent at the right angle for cleavage Halloysites were extensively fanning out and greatly increased the volume of grain. This indicated that halloysite tubes were formed by epitaxial overgrowth on the surface of biotite with import of Si and Al from the external solution by dissolution of plagioclase. These halloysites have abnormally high Fe content ( ~11%).

• Geophysics and Geophysical Exploration
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• v.14 no.1
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• pp.50-57
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• 2011

For effective and accurate prediction of overpressure in the Efomeh field, located in the Niger delta basin of Nigeria, integrated seismic and borehole analyses were undertaken. Normal and abnormal pore pressure zones were delineated based on the principle of normal and deviation from normal velocity trends. The transition between the two trends signifies the top of overpressure. The overpressure tops were picked at regular intervals from seismic data using interval velocities obtained by applying Dix's approximation. The accuracy of the predicted overpressure zone was confirmed from the sonic velocity data of the Efomeh 01 well. The variation to the depth of overpressure between the predicted and observed values was less than 10mat the Efomeh 01 well location, with confidence of over 99 per cent. The depth map generated shows that the depth distribution to the top of the overpressure zone of the Efomeh field falls within the sub-sea depth range of 2655${\pm}$2m (2550 ms) to 3720${\pm}$2m (2900 ms). This depth conforms to thick marine shales using the Efomeh 01 composite log. The lower part of the Agbada Formation within the Efomeh field is overpressured and the depth of the top of the overpressure does not follow any time-stratigraphic boundary across the field. Prediction of the top of the overpressure zone within the Efomeh field for potential wells that will total depth beyond 2440m sub-sea is very important for safer drilling practice as well as the prevention of lost circulation.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.567-576
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• 2017

In a performance-based design, the structural safety is estimated from pre- defined damage states and corresponding damage indices. Both damage states and damage indices are well defined for above-ground structures, but very limited studies have been performed on underground structures. In this study, we define the damage states and damage indices of a cut-and-cover box tunnel which is one of typical structures used in metro systems, under a seismic excitation from a series of inelastic frame analyses. Three damage states are defined in terms of the number of plastic hinges that develop within the structure. The damage index is defined as the ratio of the elastic moment to the yield moment. Through use of the proposed index, the inelastic behavior and failure mechanism of box tunnels can be simulated and predicted through elastic analysis. In addition, the damage indices are linked to free-field shear strains. Because the free-field shear strain can be easily calculated from a 1D site response analysis, the proposed method can be readily used in practice. Further studies are needed to determine the range of shear strains and associated uncertainties for various types of tunnels and site profiles. However, the inter-linked platform of damage state - damage index - shear wave velocity - shear strain provides a novel approach for estimating the inelastic response of tunnels, and can be widely used in practice for seismic designs.

• Geophysics and Geophysical Exploration
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• v.2 no.4
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• pp.167-173
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• 1999

Since the resolution of the 2-D hole-to-hole seismic traveltime tomography is affected by the limited ray transmission angle, various methods were used to improve the resolution. Linear traveltime interpolation(LTI) ray tracing method was chosen for forward-modeling method. Inversion results using the LTI method were compared with those using the other ray tracing methods. As an inversion algorithm, SIRT method was used. In the iterative non-linear inversion method, the cost of ray tracing is quite expensive. To reduce the cost, each raypath was stored and the inversion was performed from this information. Using the proposed method, fast convergence was achieved. Inversion results are likely to be affected by the initial velocity guess, especially when the ray transmission angle was limited. To provide a good initial guess for the inversion, generalized regression neural network(GRNN) method was used. When the transmitted raypath angle is not limited or the geological model is very complex, the inversion results are not affected by initial velocity model very much. Since the raypath angles, however, are limited in most geophysical tomographic problems, the enhancement of resolution in tomography can be achieved by providing a proper initial velocity model by another inversion algorithm such as GRNN.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.553-560
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• 2020

In the existing research paper, we developed Mechanical Pressurizing Equipment(MPE) that can apply a certain amount of pressure and found out about improving the bonding strength of repair materials constructed in the repair section, and if pressurized, the bonding strength could be increased. In this study, the pressure of Mechanical Pressurizing Equipment(MPE) was changed to 0, 10, 30, 50, and 80 kPa, and the test was conducted to select effective pressure by measuring the flexural, compressive, and bonding strength of the specimens and deformation of the pressure plate at the age of 3 and 28th days. As a result of the test, 30 kPa was the most efficient pressure for the MPE. After producing the specimen with three types of repair materials with different main components, the bonding strength was measured according to dry and wet conditions, construction site (ceiling, wall and floor), and whether or not pressurized, on the 3rd, 7th, 14th, and 28th, indicating that the repair materials mixed with cellulose fiber was most effective for the MPE.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.3
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• pp.1-12
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• 2004

Due to the 1989 Loma Prieta, 1995 Hyogoken Nambu earthquakes, etc, a number of bridge columns  were collapsed in flexure-shear failures as a consequence of the premature termination of the column longitudinal reinforcement. Nevertheless, previous researches for the performance of bridge columns were concentrated on the flexural failure mode. It is well understood that the seismic behaviour of RC bridge piers was dependent on the performance of the plastic hinge of RC bridge piers, the ductility of which was desirable to be computed on the basis of the curvature. Experimental investigation was made to evaluate the variation of the curvature of the plastic hinge  region for the seismic performance of earthquake-damaged RC columns in flexure-shear failure mode. Seven test specimens in the aspect ratio of 2.5 were made with test parameters: confinement ratios, lap splices, and retrofitting FRP materials. They were damaged under series of artificial earthquakes that could be compatible in Korean peninsula. Directly after the pseudo-dynamic test, damaged columns were retested under inelastic reversal cyclic loading under a constant axial load, $P=0.1f_{ck}A_g$. Residual seismic capacity of damaged specimens was evaluated by analzying the moment-curvature hysteresis and the curvature ductility. Test results show that the biggest curvature was developed around 15cm above the footing, which induced the column failure. It was observed that RC bridge specimens with lap-spliced longitudinal steels appeared to fail at low curvature ductility but significant improvement was made in the curvature ductility of RC specimens with FRP straps wrapped around the plastic hinge region. Based on the experimental variation of the curvature of RC specimens, new equivalent length of the plastic hinge region was proposed by considering the lateral confinement in this study. The analytical and experimental relationship between the displacement and the curvature ductility were compared based on this proposal, which gave excellent result.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.234-243
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• 1992

Fatigue crack initiation life has a wide scatter and this makes the fatigue design of structural members difficult. In order to make the fatigue life distribution clear, it is required to prepare a large number of specimens and repeat the fatigue tests under the same loading condition. Such fatigue tests usually take much time and cost. In this study, a fatigue testing method using a multi-notched test specimen for the purpose of estimating the distribution function of fatigue crack initiation life by small number of fatigue tests is used. The purpose of this study is to verify the above fatigue testing method of a multi-notched specimen by using Bayesian reliability analysis, Least square method and Skewness method for the determination of unknown Weibull parameters. The multi-notched specimen is a specimen in which several tens of statistically identical notches are prepared.

• Journal of the Korean Geotechnical Society
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• v.34 no.2
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• pp.55-63
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• 2018

In order to support the load of the train with enough stiffness, a study on an effective method for the characterization of the stiffness of the compacted subgrade is required. In this study, the crosshole-type dynamic cone penetrometer (CDCP) is used for the stiffness characterization of the subgrade along the depth. For the application of the CDCP test, three points of compacted subgrades are selected as the study sites. For the study sites, CDCP test, in-situ density test, and light falling weight deflectometer (LFWD) test are conducted. As the results of CDCP tests, shear wave velocity profiles are obtained by using the travel times and the travel distances of the shear waves along the depth. In addition, maximum shear modulus ($G_{max}$) profiles are estimated by using the density of the subgrades and the shear wave velocity profiles. The averaged maximum shear moduli at each testing point are highly correlated with the dynamic deflection moduli ($E_{vd}$) determined by LFWD tests. Therefore, a reliable stiffness characterization of the subgrade can be conducted by using CDCP tests. In addition, because CDCP characterizes the stiffness of the subgrade along the depth rather than a representative value, CDCP test may be effectively used for the stiffness characterization of the subgrade.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.602-608
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• 2019

The purpose of this study was to calculate the temperature difference of the sectional elevation according to the asphalt thickness of the steel box girder bridge deck and provide data on the design basis accordingly. Asphalt thicknesses produced four steel box girder model specimens of 0mm, 50mm, 100m and 150mm. In each model, 17 to 23 temperature sensors were attached to upper concrete and steel box girders. Six temperature gauges were selected to compare the temperature difference with Euro codes. The maximum and lowest temperature were calculated at the reference atmospheric temperature of each model, and the temperature difference (slope) was calculated based on this calculation. Four models of temperature difference are presented at each model. The 0mm to 100mm temperature difference models showed a -0.9 to -1.5 degree lower temperature difference compared to the temperature difference of Euro codes at the top of the slab. Overall, the measured temperature difference was found to be between 5.45% and 8.33% compared to the Euro code. The standard error coefficient, which was calculated by multiplying the average temperature with the standard error, was calculated from a range of 2.50 to 2.51 times the average at the top and bottom. It is estimated that the proposed temperature difference model can be used as a basic data when calculating temperature difference criteria for bridges in Korea.