• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.905-911
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• 2007

In this paper, geometrically and materially non-linear finite element analyses were performed to study the crease behavior of thin membranes. The cross-section of the membrane was modeled with 2-dimensional plane strain elements. To simulate the creasing process, the membrane mesh was folded, compressed to prescribed crease gauge by activating two rigid contact surfaces, and then released to give the crease topology. Various crease gauges were considered to investigate the effect of crease intensity on the initial deployment angle. The crease geometry was also obtained by experiments and the results were compared.

• Korean Institute of Interior Design Journal
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• no.22
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• pp.123-131
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• 2000

The purpose of this study is to propose a new design concept and properties within new paradigm. Contemporary students of architectural design seem to redefine the mechanic and reductive approach to design method based upon Euclidean geometry. In this study, the organic space-time and holistic view-point that constitutes the background for all this is radically different from the modern design. It consists of three sections as follow: First, it presents a concept of complex system and properties of complexity that we find in new natural science and tries to combine that news geometry with architectural design to provide a methodological basis for morphogenesis and transformation. Second, the complexity in architecture is defined as a fractal shape, folded space, and irreducible organic system that cannot be fully understood by modernist idea of architecture. Third, the complexity in architecture is strategy based on the electronic paradigm that would enable the emergence of creative possibility. The complexity theory offer new insights to explain not only natural laws but also define dynamic architecture. In fine, this study places a great emphasis on the organic world-view to the spatial organization, which I hope will contribute to generating a greater number of creative possibilities for design.

• Applied Microscopy
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• v.17 no.1
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• pp.1-15
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• 1987

Testes from the allied rock wallaby(Petrogale assimilus) have been examined by the electron microscopy in thin sections in order to examine spermiogenesis and structure of spermatozoa. The spermiogenesis can be divided into nine stages: early Golgi, late Golgi, collapsing, nuclear protrusion, condensation and flattening, nuclear shaping, rotation, nuclear ring contraction, and maturation. The acrosome has been abruptly formed following the collapse of expanded acrosomal vesicle without the cap stage described in the eutheria. The flatly condensed nucleus rotates obliquely to the axis of the axial filament complex and the folded acrosome covers the anterior third of the dorsal nuclear surface forming a wide subacrosormal space as the nuclear ring has contracted. The Sertoli cell reaction and spur are prominent during the nuclear protrusion and rotation stages. A mature spermatozoon has S-shape head which has an extended part reaching to the vicinity of the middle piece.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.365-371
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• 2010

The fins of a missile which is folded within a canister are deployed according to a command during the missile flight. The aerodynamic load generated by operating environments such as missile flight speed, platform movement speed and wind acts as an anti-deploying force and prevents the fins from deploying. As the diversification of platforms and the higher speed of missiles need a larger deploying force but the space for operating the fin deploying device is getting narrower, the new design concepts are required for developing such a device. In this study, a pneumatic device for deploying missile fins is designed and its characteristics are verified through experiments and analyses.

• Bulletin of the Korean Chemical Society
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• v.5 no.1
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• pp.23-26
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• 1984

The crystal structure of phthalylsulfacetamide, one of the long-acting 'sulfa' drugs, has been determined by the X-ray diffraction methods. The crystal is monoclinic with cell dimensions of a = 7.980(3), b = 12.784(2), c = 18.064(7) ${\AA}$ and ${\beta}$= $112.94(2)^{\circ}$, space group $P2_1$/c and Z = 4. The structure was solved by the direct methods and refined to R = 0.048. The sulfonylacetamide moiety is folded with respect to the central phenyl ring and the benzamide and benzoyl planes are nearly perpendicular to each other. This conformation is consistent with those of the relevant molecules containing the corresponding moieties. All of the molecules in the crystal lattice are connected by a three-dimensional hydrogen bonding network.

• ETRI Journal
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• v.45 no.6
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• pp.1046-1055
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• 2023

We introduce a display for virtual-reality (VR) fire training. Firefighters prefer to wear and operate a real breathing apparatus while experiencing full visual immersion in a VR fire space. Thus, we used a thin head-mounted display (HMD) with a light field and folded optical system, aiming to both minimize the volume for integration in front of the face into a breathing apparatus and maintain adequate visibility, including a wide viewing angle and resolution similar to that of commercial displays. We developed the optical system testing modules and prototypes of the integrated breathing apparatus. Through iterative testing, the thickness of the output optical module in front of the eyes was reduced from 50 mm to 60 mm to less than 20 mm while maintaining a viewing angle of 103°. In addition, the resolution and image quality degradation of the light field in the display was mitigated. Hence, we obtained a display with a structure consistent with the needs of firefighters in the field. In future work, we will conduct user evaluation regarding fire scene reproducibility by combining immersive VR fire training and real firefighting equipment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.601-609
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• 2014

Large number of SAR(Synthetic Aperture Radar) satellites, one type of earth observation satellite, have been developed as they have the advantage of not being affected by surrounding environment during the earth image acquisition. In order to gain high image quality, SAR antenna should have large diameter. However, internal space of satellite launch vehicle is limited and this leads SAR antenna to be designed deployable so that it can be folded in launch vehicle and unfolded in space. In this research, values of various design factors of deployable satellite antenna were chosen considering satellite's target mission. Configuration of deployable satellite antenna was designed by applying the chosen values of design factors, and variation in deployable satellite antenna during satellite maneuver was observed through simulation.

• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.63-72
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• 2022

The purpose of this paper was to understand the dynamics of deployment of large mesh antennas, and to provide a numerical method for determining the dynamic stiffness and the driving forces for the design. The deployment structure was numerically modeled using the frame elements. The eigenvalue analysis was demonstrated, with respect to the folded and unfolded configurations of the antenna. A multibody dynamic model was formulated with Kane's equation, and simulated using the pseudo upper triangular decomposition (PUTD) method for resolving the constrained problem. Based on the multibody model, the kinetics of the deployment, the motor driving forces, and the feasibility of the designed deployment structure were investigated.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.6
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• pp.533-539
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• 2015

Recently, guided missiles applies folding wings to save space. During wing deployment, aero force acting on wing effects significantly on deployment performance, usually aerodynamic coefficient are calculated by CFD analysis. However, Missile Datcom can calculates estimated aerodynamic coefficient very quickly by assuming wing deployment motions as dihedral angle of wing. If missile has external store, wings may need to be folded on top of each other. In this case, one of wing help or interrupt other wing deployment, locking effect. In this study, both effects were included on wing deployment performance analysis to criteria for wings locked condition and formulated wing deploy performance, and compared with wind tunnel test data. Analysis predicted vulnerable wind direction of wing deployment very well.

• Journal of architectural history
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• v.19 no.6
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• pp.233-250
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• 2010

Jukseoru as an official pavilion of the government, one of the eight sceneries in Gwndong Area, is located on the cliff over Osipcheon River. This paper interprets form and space of the pavilion with restored old life by analyzing pictures of official party in 18th century in Chosun Dynasty. Every part of the space is occupied by persons by the class and duty: the pricipal guest, nobles, subordinates, gisaengs, court musicians, and guards from the high to the low and from the inside to the outside. Applying the analysis to the Jukseoru pavilion, the noblest lord takes sit on the platform in front of folded screen at main bay under checked ceiling, enclosed by low timber beam. The next northern end bay is a place for subordinates' and servants' waiting for preparation for rice wine. Southern end entrance bay is not a result of later addition but deliberately and originally made for lower place outside the railing of wooden floor: for a waiting woman gisaeng, and subordinates. Outside under the eaves on the platform with bedrock, artificial stone and soil is a place for court musicians, subordinates, and guards. The yard in front of the building is a place for preparing meals by cookers. Every detailed ornamental form is different each other by the place for the occupied class. Existing theory tells that the building, 7 bays gable-and-hipped roof, is a result of structural extention of 2 bays at the 5 bays gabled-roof. However, through the interpretation of old pictures and application to the pavilion, the present Juseoru is not a result of later structural addition, but deliberately designed creation suited to life in hierarchical traditional society.