• Journal of the Korean Wood Science and Technology
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• v.40 no.1
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• pp.26-37
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• 2012

Recently, the demand and supply on the Hanok have been increased. However, Hanok should be requested larger section of structural members because of excessive roof weight. So, structural skin-timber was manufactured to get a lightweight structural member. The structural skin-timber has exterior shape with larger section but a great volume of wood be removed. The reduced strength of structural skin-timber can be supplemented by hybridizaion of structural member. Japanese larch and Domestic pine were used to manufacture the structural skin-timber. Structural skin-timbers of rectangular shape and cylinder shape were manufactured and tested to evaluate the bending properties. The intended strength property could not be obtained because member had been suffered severe damage by precision deficiency of manufacturing machine. However, if precision of manufacturing machine would be improved and additional hybridizaion of structural skin-timber would be done, lightweight structural member will be able to be manufactured. Structural skin-timber did not showed statistical significancy between two species, so it is possible to use pine mixed with larch. Only MOR of larch showed statistical significancy between rectangular shape and cylinder shape, so it is necessary to use of those as separate things. However, the rest of skin-timber can be judged mixed using because of non statistical significancy. The objective of this study was the development of lightweight larger structural member with relatively strength. If hybrid member of skin-timber could be developed with wood-ceramics, lightweight steel and more, it can be possible to be used as a building material of Hanok, interior material, post & beam construction material and more.

• Biomedical Science Letters
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• v.27 no.4
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• pp.231-238
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• 2021

Several structural proteins present in keratinocytes of the skin are known to play an important role in the formation of epidermal tissue and barrier function, and the absence of structural proteins in keratinocytes causes various skin diseases. In this study, 42 types of tetrapeptides derived from the sequence of Loricrin, a kind of terminally differentiating structural protein, were synthesized, and skin anti-aging properties were measured by measuring the elastase inhibition, proliferation of skin cells. The anti-aging efficacy was verified and, based on this, it succeeded in selecting one of the most excellent peptides. It is expected that the selected tetrapeptide can be used as a raw material for various cosmetics and quasi-drugs based on anti-aging and skin cell proliferation effects.

• Journal of the Korea Furniture Society
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• v.21 no.4
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• pp.273-283
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• 2010

Structural larger timber have some weak points as like much longer drying time at lower MC(15%), a considerable check developing and the difficulty for the chemicals injection, so it is necessary to develop lighter structural size member for using the new Hanok, heavy timber construction, living necessaries, furniture and industrial goods. The developed skin timber can be a good raw material for those uses. Skin timber is a hollowed timber which be bored out of its considerable cross-sectional area. The intention of this study was the evaluation of compressive capacity of skin timber. Specially, skin timbers which have more than 200mm in sizes were used to analyze the compressive capacity. From the results of this study, the following conclusions have been made: 1. Though considerable inner parts were bored out, both pine skin timber and larch skin timber showed a good compressive capacity to that of non-bored solid timber. 2. According to ASTM, pine skin timber showed various failure types, but Splitting type, Brooming and end rolling type were main failure types for the larch skin timber. 3. Pine skin timber didn't show the significance between cylindrical shape and rectangular shape, but larch skin timber showed the significance between two shapes. Therefore, for the larch skin timber, cylindrical shape and rectangular shape should be used as a column uses and beam uses respectively. 4. Pine skin timber and larch skin timber didn't show the significance on the compressive capacity. There is not much difference of compressive capacity between them, so it can be possible to select on the user convenience.

• International Journal of High-Rise Buildings
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• v.7 no.1
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• pp.17-32
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• 2018

This paper explores the function of a structural skin with an embossed surface applicable to use for tall building structures. The major diagrid system with a secondary embossed surface structure provides an enhanced perimeter structural system by increasing tube section areas and reduces aerodynamic loads by disorienting major organized structure of winds. A parametric study used to investigate an optimized configuration of the embossed structure revealed that the embossed structure has a structural advantage in stiffening the structure, reducing lateral drift to 90% compared to a non-embossed diagrid baseline model, and results of wind load analysis using computational fluid dynamics, demonstrated the proposed embossed system can reduce. The resulting undulating embossed skin geometry presents both opportunities for incorporating versatile interior environments as well as unique challenges for daylighting and thermal control of the envelope. Solar and thermal control requires multiple daylighting solutions to address each local façade surface condition in order to reduce energy loads and meet occupant comfort standards. These findings illustrate that although more complex in geometry, architects and engineers can produce tall buildings that have less impact on our environment by utilizing structural forms that reduce structural steel needed for stiffening, thus reducing embodied $CO^2$, while positively affecting indoor quality and energy performance, all possible while creating a unique urban iconography derived from the performance of building skin.

• Computational Structural Engineering
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• v.27 no.1
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• pp.34-40
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• 2014

• International Journal of Aerospace System Engineering
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• v.6 no.1
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• pp.1-7
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• 2019

In the present study, structural safety and stability on the main wing and tail planes of the 1.2 ton WIG(Wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The carbon-epoxy composite material was used in design of wing structure. The skin-spar with skin-stressed structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, the design load was estimated with maximum flight load. From static strength analysis results using finite element method of the commercial codes. From the stress analysis results of the main wing, it was confirmed that the upper skin structure between the second rib and the third rib was unstable for the buckling load. Therefore in order to solve this problem, three stiffeners at the buckled region were added. After design modification, even though the weight of the wing was a little bit heavier than the target weight, the structural safety and stability was satisfied for design requirements.

• Journal of the Korean Applied Science and Technology
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• v.30 no.2
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• pp.215-224
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• 2013

Recently, many cosmetic researchers have been focused on the development of high functional cosmetics including anti-wrinkle and whitening. In these studies, they couldn't afford to pay a deep attention to stable encapsulations for unstable materials and efficient drug deliveries for them. Particularly, in order to show a degree of instant effects as cosmetics, they can't also ignore moisturizing effect enough to satisfy customers just after applying and its maintenance by improving the function of skin barrier as well as above two effects. Therefore, skin analogue systems have attracted considerable attention in the view of structural and compositional similarity to intercellular membrane in stratum corneum. And, some models for skin analogue composition were developed to improve the function of skin barrier, stably encapsulate unstable materials such as retinol, vitamin B, C, E, etc., and control their skin penetration in order to show good effects as cosmetics. In this study, we suggest the new skin analogue model having the compositional similarity as well as conventional structural ones. Our skin analogue membrane(SAM) is mainly composed of ceramide/ cholesterol/phosphatidylcholin/fatty acids and its structural defects are compensated by including cholesterol amphiphile and controlling the ratio of ceramide/cholesterol. It was possible to confirm the formation of skin analogue membrane having highly-densed multilamella structure and compare them according to the change of each ratio with a polarized microscope, X-ray diffraction. More detaily, we observed their structures with a electron microscope(TEM). Finally, we dispersed them in excess of continuous water phase, observed the formation of maltese-cross liquid crystalline and measured the efficiency of drug deliveries and moisturizing effects.

• Steel and Composite Structures
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• v.22 no.5
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• pp.1141-1162
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• 2016

Concrete-filled double skin steel tube (CFDST) beam-columns are widely used in industrial plants, subways, high-rise buildings and arch bridges. The CFDST columns have the same advantages as traditional CFT members. Moreover, they have lighter weight, higher bending stiffness, better cyclic performance, and have higher fire resistance capacities than their CFT counterparts. The scope of this study is to develop finite element models that can predict accepted capacities of double skin concrete-filled tube columns under the combined effect of axial and bending actions. The analysis results were studied to determine the distribution of stresses among the different components and the effect of the concrete core on the outer and inner steel tube. The developed models are first verified against the available experimental data. Accordingly, an extensive parametric study was performed considering different key factors including load eccentricity, slenderness ratio, concrete compressive strength, and steel tube yield strength. The results of the performed parametric study are intended to supplement the experimental research and examine the accuracy of the available design formulas.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.179-184
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• 2005

In the present study, conceptual design of the main wing for 20 seats WIG{wing in Ground Effect) flight vehicle, which will be a high speed maritime transportation system for the next generation, was performed. The high stiffness and strength Carbon-Epoxy material was used for the major structure and the skin-spar with a foam sandwich structural type was adopted for improvement of lightness and structural stability. As a design procedure for this study, firstly the design load was estimated with maximum flight load, and then flanges of the front and the rear spar from major bending load and the skin structure and the webs of the spars were preliminarily sized using the netting rules and the rule of mixture. In order to investigate the structural safety and stability, stress analysis was performed by Finite Element Codes such as NASTRAN/PA TRAN[6] and NISA II [7]. From the stress analysis results, it was confirmed that the upper skin structure between the front spar and rear spar was very unstable for the buckling. Therefore in order to solve this problem, a middle spar and the foam sandwich structure at the upper skin and the web were added. After design modification, even thought the designed wing weight was a little bit heavier than the target wing weight, the structural safety and stability of the final design feature was confirmed. Moreover, in order to fix the wing structure at the fuselage, the insert bolt type structure with six high strength bolts was adopted for easy assembly and removal.

• Structural Engineering and Mechanics
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• v.54 no.1
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• pp.121-133
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• 2015

The aluminum dome has been widely used in natatorium, oil storage tank, power plant, coal, as well as other industrial buildings and structures. However, few research has focused on the structural behavior and design method of this dome. At present, most designs of aluminum alloy domes have referred to theories and methods of steel spatial structures. However, aluminum domes and steel domes have many differences, such as elasticity moduli, roof structures, and joint rigidities, which make the design and analysis method of steel spatial structures not fully suitable for aluminum alloy dome structures. In this study, a stability analysis method, which can consider structural imperfection, member initial curvature, semi-rigid joint, and skin effect, was presented and used to study the stability behavior of aluminum dome structures. In addition, some meaningful conclusions were obtained, which could be used in future designs and analyses of aluminum domes.