• Journal of Astronomy and Space Sciences
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• v.15 no.1
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• pp.209-220
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• 1998

The stability problem of steady motion of a rigid body with multi-elastic appendages and multi-liquid-filled cavities, in the presence of no external forces or torque, is considered in this paper. The flexible appendages are modeled as the clamped -free-free-free rectangular plates, or/and as the discrete mass- spring sub-system. The motion of liquid in every single ellipsoidal cavity is modeled as the uniform vortex motion with a finite number of degrees of freedom. Assuming that stationary holonomic constraints imposed on the body allow its rotation about a spatially fixed axis, the equation of motion for such a systematic configuration can be very complex. It consists of a set of ordinary differential equations for the motion of the rigid body, the uniform rotation of the contained liquids, the motion of discrete elastic parts, and a set of partial differential equations for the elastic appendages supplemented by appropriate initial and boundary conditions. In addition, for such a hybrid system, under suitable assumptions, their equations of motion have four types of first integrals, i.e., energy and area, Helmholtz' constancy of liquid - vortexes, and the constant of the Poisson equation of motion. Chetaev's effective method for constructing Liapunov functions in the form of a set of first integrals of the equations of the perturbed motion is employed to investigate the sufficient stability conditions of steady motions of the complete system in the sense of Liapunov, i.e., with respect to the variables determining the motion of the solid body and to some quantities which define integrally the motion of flexible appendages. These sufficient conditions take into account the vortexes of the contained liquids, the vibration of the flexible components, and coupling among the liquid-elasticity solid.

• Journal of Astronomy and Space Sciences
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• v.19 no.1
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• pp.47-56
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• 2002

Observations of times of minimum lights of the eclipsing binary V65l Cas were carried out on the three nights from November 21-23, 2000. From our observations a total of seven new times of minimum lights was obtained. Through the analysis of photoelectric and CCD times of minima of V65l Cas including ours, the light time orbit due to a third body, which was propose by Kim ＆ Lee (2000), was confirmed and improved. The resultant values for the period, semi-amplitude, and eccentricity of the light-time orbit were $6.^{y}3,\;0.^{d}0013$, and 0.78, respectively. The deduced marts range of the third body is . If the third body is $0.09M_{\odot}\;{\leq}\;M_3\;{\leq}\;0.20M_{\odot}\;for\;i_3\;{\geq}\;30^{\circ}$. If the third body suggested in V65l Cas system exists really and is a main-sequence star, it is located at the end of the main-sequence.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.3
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• pp.233-240
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• 2017

The flowfield around transonic wing-body configuration was simulated using in-house CFD code and compared with the experimental data to understand the influence of several features of CFD(Computational Fluid Dynamics) ; grid dependency, turbulence models, spatial discretization, and viscosity. The wing-body configuration consists of a simple planform RAE Wing 'A' with an RAE 101 airfoil section and an axisymmetric body. The in-house CFD code is a compressible Euler/Navier-Stokes solver based on unstructured grid. For the turbulence model, the $k-{\omega}$ model, the Spalart-Allmaras model, and the $k-{\omega}$ SST model were applied. For the spatial discretization method, the central differencing scheme with Jameson's artificial viscosity and Roe's upwind differencing scheme were applied. The results calculated were generally in good agreement with experimental data. However, it was shown that the pressure distribution and shock-wave position were slightly affected by the turbulence models and the spatial discretization methods. It was known that the turbulent viscous effect should be considered in order to predict the accurate shock wave position.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.692-698
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• 2015

This paper represents a trajectory design and analysis technique which uses invariant manifolds of the circular restricted three body problem. Instead of the classical patched conic method based on 2-body problem, the equation of motion and dynamical behavior of spacecraft in the circular restricted 3-body problem are introduced, and the characteristics of Lyapunov orbits near libration points and their invariant manifolds are covered in this paper. The trajectories from/to Lyapunov orbits are numerically generated with invariant manifolds in the Earth-moon system. The trajectories in the Sun-Jupiter system are also analyzed with various initial conditions in the boundary surface. These methods can be effectively applied to interplanetary trajectory designs.

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.5
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• pp.675-689
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• 2014

This study developed an ideal jeggings pattern with an improved body fit for 20-24 year old females. The results of the study are as follows. First, samples for wearing test were made using jegging patterns from three manufacturers; subsequently, one pattern with a relatively outstanding body fit was selected from the first test. The selected pattern suggested a tight knee, belly, and crotch, high front waist line, and low back waist line. The side lines were also lean to the front; consequently, the front hip width was extended for 0.5cm for more space around the belly and the extended front knee part for 0.2cm to increase moving suitability to fix the leaning side lines. A 1cm front waist line was extended for 0.5cm to fix it lower; in addition, the back waist line 3.0cm was extended for 0.5cm to heighten it. The crotch width was also extended for 0.5cm to add more space. The second wearing test for the fixed forms were evaluated for their outstanding features in appearance as well as moving functions that were proposed as final jeggings forms. The results of the study suggested a jeggings pattern with a better body fit using manufacturer patterns that can be used as basic data for pant patterns with better fitting using various stretch fabrics.

• Journal of the Korean Home Economics Association
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• v.39 no.8
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• pp.137-154
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• 2001

This study was made to draft the tight fitting bodice pattern which horizontal and perpendicular stands are to be lightly set, with the consideration of characteristics of body shape in design of clothes. Measurement of body was conducted on 53 women in twenties, and observation was made on surface development pattern by adhesive tape addition method and gypsum method on three standard objects. In the study, bodice pattern was completed by using already made Somato- measurer, compared with existing bodice pattern, and the results are as follows. The result of the correlation analysis by body measurement shows that chest circumference has a relation to B$.$P-front neck point, side neck point, shoulder point, front interscye breadth point, and the item in spine scapulae point has relation to the item of back neck line, and front & back horizontal values. The degree of shoulder slant, width of armhole and of its depth, the amount of breast, back space, back length were shown to be directly measured from the body. In surface development pattern, tight-fit bodice pattern necessary to the breast volume and back space were shown to be investigated and these volume have to be given in setting up basic line for clothes design together with body measurement value. The result of sensory evaluation for appearance test on fitness shows higher value of research bodice including line of shoulder line, front and back interscye breadth, chest circumference, waist circumference, armhole circumference and of its depth, compared with the research bodice in most items. The result of this study is seen showing high effectiveness for the basic data to design the ready-made dress of high sensitivity of high value added tat.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.984-991
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• 2009

In this study, transonic aeroelastic response analyses have been conducted for the DLR-F4(wing-body) aircraft configuration considering shockwave and flow separation effects. The developed fluid-structure coupled analysis system is applied for aeroelastic computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. It can give very accurate and useful engineering data on the structural dynamic design of advanced flight vehicles. For the nonlinear unsteady aerodynamics in high transonic flow region, Navier-Stokes equations using the structured grid system have been applied to wing-body configurations. In transonic flight region, the characteristics of static and dynamic aeroelastic responses have been investigated for a typical wing-body configuration model. Also, it is typically shown that the current computation approach can yield realistic and practical results for aircraft design and test engineers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.674-679
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• 2005

This paper is concerned with the application of perturbation method to the dynamic analysis of space structure floating in space. In dealing with the dynamics of space structure, the use of Lagrange's equations of motion in terms of quasi-coordinates were suggested to derive hybrid equations of motion for rigid-body translations and elastic vibrations. The perturbation method is then applied to the hybrid equations of motion along with discretization by means of admissible functions. This process is very tiresome. Recently, a new approach that applies the perturbation method to the Lagrange's equations directly was proposed and applied to the two-dimensional floating structure. In this paper, we propose the application of the perturbation method to the Lagrange's equations of motion in terms of quasi-coordinates. Theoretical derivations show the efficacy of the proposed method.

• Journal of architectural history
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• v.11 no.1 s.29
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• pp.33-48
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• 2002

The purpose of this study is to analyze the Daniel Libeskind' spatial concept in view of the Merleau-Ponty's Phenomenology. After the coming of postmodern architecture, the concept of space ceased to be discussed between architects. Instead a sign and a form were supposed as much more important subject to define architectural discipline. But after 1980, the new concept of architectural space was experimented by the architects like Frank Gehry, Peter Eisenman, Steven Hall, and Bernard Tschumi, which was clearly distinguished from modern spatial concept. By the Daniel Libeskind' architecture, this study are to make clear this tendency. For this, we accept as an important instrument Meleau-Ponty's phenomenology and the spatial concept of Minimalism, which stress the relationship of inter-subjectivity between space and human body. Consequently, Daniel Libeskind' spatial concept is characterized by fragmental, accidental, heterogeneous space by accidental events which is occurred by movement of human, which was indentified with Merleau-Ponty's spatial concept.

• Journal of the Korean Society of Costume
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• v.59 no.9
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• pp.163-179
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• 2009

The superimposition of the Russian constructivist architectural design is one of the notable transforming techniques of conventional design principles. The main objective of this paper is to analyse the superimposed space in the modern fashion design based on the techniques and characteristics of superimposition appeared in Russian constructivism architectural space. The artistic characteristics of the superimposed design in the modern fashion design can be determined by codes of dynamics, sense of space, rhythmical sense, communications and tension of the dress. Through this study, it was found that superimposition of the Russian constructivist architectural design in the modern fashion design has influenced the modern fashion design space in the forms of dynamics with directive sense, vitality through transparency, uniformity with geometric interpenetrates, intensive visual attraction created by duplicity, communication between human body and clothes, creation of transformative beauty and enhancement of structural volume on clothes.