• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.194-199
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• 2005

Body-on-frame type vehicle has a set of frame bushes which are installed between body and frame fur vibration Isolation. Such frame bushes are important vibration transmission paths to passenger space. In order to reduce the vibration level of passenger space, therefore, the change of complex stiffness of the frame bushes is more efficient than modification of other parts of the vehicle such as body, frame and suspension. The purpose of this study is to reduce the vibration level for ride comfort by optimization of complex stiffness of frame bushes. In order to do this end, simple finite element vehicle model was constructed and the complex stiffness of frame bushes was set to be design variable. Objective function was defined to reflect passenger ride comfort and genetic algorithm and sub-structure synthesis were applied for minimization of the objective function.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.6 s.111
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• pp.619-626
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• 2006

Body-on-frame type vehicle has a set of frame bushes between body and frame for vibration isolation. Such frame bushes are important vibration transmission paths to passenger space for excitations during driving. In order to reduce the vibration level of passenger space, therefore, change of complex stiffness of the frame bushes is more efficient than modification of other parts of the vehicle such as body, frame and suspension. The purpose of this study is to reduce the vibration level for ride comfort by optimization of complex stiffness of frame bushes. In order to do this, a simple finite element vehicle model was constructed and complex stiffness of the frame bushes was set to be design variables. The objective function was defined to reflect frequency dependence of passenger ride comfort. Genetic algorithm and sub-structure synthesis were applied for minimization of the objective function. After optimization level at a position of interest on the car body was reduced by about 43.7 % in RMS value. Causes for optimization results are discussed.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.80-85
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• 2008

This paper investigate the structure instability properties of the shelled space frame structure. The large structure must have thin thickness for build the large space structure there fore structure instability review is important when we do structural design. The structure instability of the shelled structure accept it sensitively by varied conditions. This come to a nonlinear problem with be concomitant large deformation. In this study, it is compared unstable behavior according to lode and boundary condition of the shelled space frame structure through numerical method which considered geometrical nonlinear and grasped influence for the instability phenomenon and investigated the fundamental collapse mechanism.

• Structural Engineering and Mechanics
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• v.70 no.2
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• pp.221-231
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• 2019

This paper performs for the first time a simultaneous optimization for members sections along with semi-rigid beam-to-column connections for space steel frames with fixed, semi-rigid, and hinged bases using a biogeography-based optimization algorithm (BBO) and a genetic algorithm (GA). Furthermore, a member's sections optimization for a fully fixed space frame is carried out. A real and accurate simulation of semi-rigid connection behavior is considered in this study, where the semi-rigid base connections are simulated using Kanvinde and Grilli (2012) nonlinear model, which considers deformations in different base connection components under the applied loads, while beam-to-column connections are modeled using the familiar Frye and Morris (1975) nonlinear polynomial model. Moreover, the $P-{\Delta}$ effect and geometric nonlinearity are considered. AISC-LRFD (2016) specification constraints of the stress and displacement are considered as well as section size fitting constraints. The optimization is applied to two benchmark space frame examples to inspect the effect of semi-rigidity on frame weight and drift using BBO and GA algorithms.

• Korean Institute of Interior Design Journal
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• no.21
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• pp.107-113
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• 1999

The purpose of this study is to suggest the materials for developing the new house style by analysing the space characteristics of wood frame houses in suburbs of Seoul. For this, we analysed 45 drawings(site plan, floor plan, elevation, section) that were designed by MICHOO, WOOD-LAND, STUGA and CHOWONJUTECK company etc. The space design characteristics that we found are as follows; 1. The wood is fragile to humidity. Therefore this characteristic is especially considered in designing the space of bathroom and utility room. 2. It is the merit of wood frame house that inner space can be designed variously by using spilt-level and the slope of roof. 3.The public space and private space are completely separated in most cases and the stair is located in the middle of house. This structure of house is short of horizontal openness. Instead, most houses gets vertical openness by making second floor on the living room opev. 4. In wood frame house as the rural house, the outer space is well used by setting up deck and balcony. The outer spaces like deck and balcony are usually used as a part of life space in connected with living room, dining room, master bed room and family room. 5. The public spaces like kitchen, living room, dining room and family room are considered so important in design that those are arranged in front in order to have good outlook and directiov.

• IE interfaces
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• v.18 no.1
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• pp.82-87
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• 2005

Most of virtual reality systems ask users to control 3D objects or to navigate 3D world using 3D controllers. To maximize the human performance in the control, the design of virtual reality system and its input and output devices should be optimized. In this study, an experiment was designed to investigate the effects of three resolution factors of a virtual reality system on the human performance. Six subjects conducted the experiment for the factors; two frame rates, three spatial resolutions, and three pictorial contents. The result showed that the greater the spatial resolution was, the higher the human performance was. For the temporal resolution, fixed frame rate at 18 Hz was better than the varied maximized frame rate. For the pictorial contents, the virtual space with orientation cues marked the greatest performance than the other two conditions; the virtual space without any orientation cue and the virtual space like real world. These results could be applied for the design of virtual reality systems.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.348-355
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• 2000

The characteristics on non linear behavior and the failure mechanism of RC space frame structure serving railway under seismic action have been investigated by numerical analysis in time domain. The structure concerned is modeled in 3 dimensional extent and RC frame elements with fibers are employed. Fibers are characterized as RC one and PL one to distinguish different energy release after cracking. Due to deviation of mass center and stiffness center of entire structure the complex behavior under seismic action is shown. The excessive shear force is concentrated on the pier beside flexible one relatively, which leads to failure of bridge concerned.

• Bulletin of the Korean Mathematical Society
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• v.50 no.6
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• pp.1841-1846
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• 2013

In this paper we establish some new results on sums of Hilbert space frames and Riesz bases. We also provide a correction to some recently established results in [2].

• Honam Mathematical Journal
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• v.29 no.1
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• pp.1-8
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• 2007

In this paper we show that for each finite frame for a Hilbert space there are two orthonormal elements related to the optimal lower and upper bounds of the frame. Based on this we show that an orthonormal basis is naturally associated with every finite frame. We then analyze the relationship between such an orthonormal basis and the given finite frame.

• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.595-618
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• 2010

To grow as talents with future oriented knowledge and creativity, students need imaginative power and creativeness, and to that end, mathematics and science subjects may help. Students need activities that help gain explorative mind for new things, concentrating ability, researching ability and creativeness, and such attributes can be improved through the activities of making various shapes utilizing space geometry in 4D-frame. Such activities not only contribute to defining ability in mathematics but also cherish the qualifications required as architects and space scientists.