• Economic and Environmental Geology
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• v.47 no.2
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• pp.107-119
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• 2014

NMC Moland mine, which is classified as a contact replacement or skarn deposit, has been interpreted to have been formed by Daebo igneous activity which intruded into the Joseon Supergroup, because it is quite closely located to Jecheon granite. However, an alternative interpretation was recently suggested that the mine could be related with the hydrothermal fluid originated from Cretaceous granitic rocks, bringing about skarnization and Mo mineralization. Here we present an interpretation on the source granite of the mine based on the gravity exploration: the gravity anomaly, unlike the surface geology, shows that the Muamsa granite could be the related granite of the mine, because its hidden subsurface structure is expected to be more widely extended to surrounding area of the mine and deeper than the Jecheon granite.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.524-527
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• 1988

Basic types of bilateral servo systems were described and practical consideration in the bilateral servo controller design was introduced. Power assistance to the operator is essential for high efficiency and accurate force reflection is necessary for dexterous manipulation. This paper shows a controller structure under development at KIMM which employs nonlinear friction compensation and memory based gravity compensation technique for efficiency and dexterity.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.274-281
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• 2002

In this study a analytical model for a structure with buckling-restrained unbonded knee-braces is proposed, and a performance-based seismic design procedure for such a system Is provided. The proposed structure system has advantage of simplifying the structural design procedure in that the hinge-connected main structural members, such as beams and columns, are designed only for gravity loads, and all the lateral seismic load is resisted by the braces. The design procedure is based on the concept of equivalent damping, and is implemented to the capacity spectrum method. Parametric study is performed with design variables such as yield stress and cross-sectional area of knee-braces to find out proper slope of the braces.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.132-138
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• 2016

Korea Aerospace Research Institute (KARI) is developing an electric-driven HALE UAV in order to secure system and operational technologies since 2010. Based on the flight tests and design experiences of the previously developed electric-driven UAVs, KARI has designed EAV-3, a solar-powered HALE UAV. EAV-3 weighs 53kg, the structure weight is 22kg, and features a flexible wing of 19.5m in span with the aspect ratio of 17.4. Designing the main wing and empennage of the EAV-3 the amount of the bending due to the flexible wing, 404mm at 1-G flight condition based on T-800 composite material, and side wind effects due to low cruise speed, $V_{cr}=6m/sec$, are carefully considered. Also, unlike the general aircraft there is no center of gravity shift during the flight because of the EAV-3 is the solar-electric driven UAV. Thus, static margin cuts down to 28.4% and center of gravity moves back to 31% of the Mean Aerodynamic Chord (MAC) comparing with the previously designed the EAV-2 and EAV-2H/2H+ to upgrade the flight performance of the EAV-3.

• The KSFM Journal of Fluid Machinery
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• v.15 no.1
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• pp.46-51
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• 2012

This study is to confirm the deformation of blade when the location of stacking is moving. Also, it desire to determine the most stable location of stacking from the analysis. In the previous study, it is Known that moving the location of stacking is not influence to the aerodynamic performance. In this study SolidWorks premium 2010 SP4 is used for structure analysis. In reference blade and other 3 model analysis, the two mesh type is used, one is standard mesh type in SolidWorks, the other is curvature-based mesh type. The result of curvature-based mesh type is more stable than one of the standard mesh type regardless of mesh size, the number of mesh. The deformation of blade tip is the smallest, when the location of stacking is identical to the center of gravity of the blade section profile. So, if possible is design, this study recommends that the location of stacking is identical to the center of gravity the blade.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.201-208
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• 2007

This paper is research results of investigating the elastic settlement behavior of the coastal caisson structure built on the sandy deposit by comparing results of centrifuge model experiments and those of existing methods of estimating elastic settlement. Basic soil property tests such as specific gravity test, grain size distribution test and organic content test with disturbed soil sampled from the site were carried out. The centrifuge experiment of model satisfying the required design criteria was performed under 50 of artificial accelerated gravitational force condition. The Centrifuge model experimental results were compared and analyzed with the current methods of estimating settlement based on the elastic modulus obtained from the results of odeometer tests and empirical methods from literature reviews.

• Structural Engineering and Mechanics
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• v.33 no.4
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• pp.407-428
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• 2009

The effects of the uniform and spatially varying ground motions on the stochastic response of fluid-structure interaction system during an earthquake are investigated by using the displacement based fluid finite elements in this paper. For this purpose, variable-number-nodes two-dimensional fluid finite elements based on the Lagrangian approach is programmed in FORTRAN language and incorporated into a general-purpose computer program SVEM, which is used for stochastic dynamic analysis of solid systems under spatially varying earthquake ground motion. The spatially varying earthquake ground motion model includes wave-passage, incoherence and site-response effects. The effect of the wave-passage is considered by using various wave velocities. The incoherence effect is examined by considering the Harichandran-Vanmarcke and Luco-Wong coherency models. Homogeneous medium and firm soil types are selected for considering the site-response effect where the foundation supports are constructed. A concrete gravity dam is selected for numerical example. The S16E component recorded at Pacoima dam during the San Fernando Earthquake in 1971 is used as a ground motion. Three different analysis cases are considered for spatially varying ground motion. Displacements, stresses and hydrodynamic pressures occurring on the upstream face of the dam are calculated for each case and compare with those of uniform ground motion. It is concluded that spatially varying earthquake ground motions have important effects on the stochastic response of fluid-structure interaction systems.

• Korean Institute of Interior Design Journal
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• no.40
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• pp.34-41
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• 2003

A purpose of this study is to comprehend a concept of 'Open Space', realization of a deconstruction, presented in his works, based on a deconstruction and surrealism Coop Himmelblau's philosophical contemplation and to look into how this concept is interpreted in spaces. A concept of 'Open Space' is functioned as not a singular meaning but a multiple meaning accompanied with other formative ingredient and contemplation, scientific paradigm and a realation with a surroundings. The concept of 'Open Space' in their architentural space is applied. First, the space openness that represents to the extreme a concept 'Open Space', as a 3D designing ways that demolishes a structure and outgrows an ex siting thinking pattern, represents multiple grade spaces and an anti-gravity space. In a material, using glass and iron provides a spacial transparency and through this, visibly liberal sense that an interior and exterior is felt as an unification. Second, an non-expressive box pattern repulses to a spatial rank nature, outgrowing an uniform geometrical system, through demolishing a geometrical system, an edge and fold pattern. This is, as an anti-gravity, dynamic a typical structure, outgrowing an orthogonal system, interpreted as a composite meaning without division in spatial area. Third, the collage is used to represent a complexity and pluralism in representing 'Open space'. The collage that forms a image through combining a fragmentary elements into being a space change, composite constitution and spatial amusement. Thus, It is worthwhile to study how the collage that forms a diverse shape will be developed making what impact as an age and surroundings changed. As we contemplate in former part, Coop Himmelblou has deployed 'deconstruction beyond deconstruction' realm as just their midterm concept in their works like the words 'The architecture must climb', the deconstructive architect. A studying for their works reflecting the 'Open Space' concept based on deconstruction must be lasted and this enables us to comprehend space concept containing an architecture and interior design.

• Journal of the Korean Geotechnical Society
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• v.35 no.4
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• pp.15-26
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• 2019

The stability of the gravity quay wall against earthquakes is evaluated on the basis of the allowable displacement of the wall. To estimate the displacement caused by external forces, empirical equations based on the Newmark sliding block method or numerical analysis are widely used. In numerical analysis, it is possible to analyze precisely a complicated site and structure, but difficult to set the appropriate parameters and environments; there are limitations in obtaining reliable results, depending on one's level of expertise. The Newmark method, with only seismic motions, is widely used because it is simpler than numerical simulations when estimating permanent displacement. However, the empirical equations do not have any parameters for the response characteristics and sliding block of the structure, and sliding blocks being assumed as rigid bodies does not consider the nonlinear behavior of the soil and interaction with the structure. Therefore, in order to evaluate the seismic stability of the gravity quay wall, a newly-developed empirical equation is needed to overcome the above-mentioned limitations. In this study, numerical simulations are performed to analyze the response characteristics of the backfill of the structure, and to propose an optimal method of calculating the active area. For this purpose, finite element analyses were performed to analyze the response characteristics, and stress-strain relationships for various seismic motions. As a result, the response characteristics, sliding block, and failure surface of the backfill vary depending on the input seismic motions.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.597-608
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• 2020

Even after the Gyeongju earthquake and the Pohang earthquake, hundreds of aftershocks and micro-earthquakes are still occurring in the southeastern part of the Korean Peninsula. These phenomena mean that the stress is constantly working, implying that another huge earthquake may occur in the future. Therefore, the gravity field interpretation method was used to analyze the deep geological structure of the Pohang-Ulsan region in the southeastern Korean Peninsula. First, a gravity survey was performed to collect the insufficient data and to calculate the detailed Bouguer gravity anomaly in the study area. Based on the gravity anomaly data, the location, direction, and maximum depth of deep fault lines were analyzed using the inversion methods "Curvature analysis" and "Euler deconvolution method". As a result, it is interpreted that at least six fault lines(C1~C6) exist in deep depth. The deep fault line C1 is well correlated to the Yeonil Tectonic Line(YTL), suggesting that YTL is extended up to about 4000m deep. The deep fault line C2 consists of several segment faults and well correlated to the fault lines on the surface. Inferred fault lines C3, C4, and C5 have an NW-SE direction, which is parallel to the Ulsan fault. The deep fault line C6 has the direction of NE-SW, and it is interpreted that the eastern boundary fault of Eoil Basin is extended to the deep. Comparing the inferred fault lines with the distribution of micro-earthquakes, the location of the deep fault line C1 is well correlated to the hypocenter of micro-earthquakes. This implies that faults in deep depth are related to the recent earthquakes in the southeastern Korean Peninsula.