• Journal of the Korean Institute of Landscape Architecture
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• v.17 no.3
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• pp.35-47
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• 1990

This study was executed to analyze the vegetational landscape structure and administration planning of Heonin Royal Tomb forest by three kinds of ordination techniques (PCA, RA and DCA) and comparison of the couple photographs between 1920s and 1980s. Seventeen sites in the recreation area and fifteen sites in the protective area were sampled with clumped sampling method in June 1988 and five quadrats were examined in each site. Environmental impact grade 3, 4 and 5 area covered 56.4% of the surveyed area and these area should be restored by the input of human energy. Pinus densifora community of actual vegetation covered 8.4%, Alnus japonica 24.2% and Quercus community 40.9% of the total area. And the afforested vegetation of Pinus koraiensis and Pinus rigida covered 23.1 % The recreation area was divided by P. densiflora, P. densiflora-Quercus aliena, A. japonica-Q.aliena, A. japonica and the protective area by Q. acutissima, Q. aliena, A. japonica-Q. aliena.. DCA ordination showed that successional trends of tree species seem to be from P. densiflora, Sorbus alnifolia, Styrax obassia to Q. variabilis Q. serrata in P. densiflora community and from A. japonica through A. ginnala to Q. aliena in A. japonica community of the upper layer. By the comparison of the couple photographs between 1920s and 1980s, we can recognize the change of historical landscape composed of P. densiflora community and those community is succeeded to Q. aliena.

• Steel and Composite Structures
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• v.30 no.3
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• pp.217-230
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• 2019

One of the most important design criteria in underground structure is to design lightweight protective layers to resist significant blast loads. Sandwich blast resistant panels are commonly used to protect underground structures. The front face of the sandwich panel is designed to resist the blast load and the core is designed to mitigate the blast energy from reaching the back panel. The design is to allow the sandwich panel to be repaired efficiently. Hence, the underground structure can be used under repeated blast loads. In this study, a novel sandwich panel, named RC panel - Helical springs- RC panel (RHR) sandwich panel, which consists of normal strength reinforced concrete (RC) panels at the front and the back and steel compression helical springs in the middle, is proposed. In this study, a detailed 3D nonlinear numerical analysis is proposed using the nonlinear finite element software, AUTODYN. The accuracy of the blast load and RHR Sandwich panel modelling are validated using available experimental results. The results show that the proposed finite element model can be used efficiently and effectively to simulate the nonlinear dynamic behaviour of the newly proposed RHR sandwich panels under different ranges of free air blast loads. Detailed parameter study is then conducted using the validated finite element model. The results show that the newly proposed RHR sandwich panel can be used as a reliable and effective lightweight protective layer for underground structures.

• ALGAE
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• v.26 no.2
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• pp.201-208
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• 2011

A monoterpene lactone, loliolide was successively isolated from brown seaweed, Sargassum ringgoldianum subsp. coreanum using column chromatography and high-performance liquid chromatography. The structure of the isolated compound was determined by comparison of EIMS and NMR spectral data with the previously published data. The antioxidant activities of loliolide were also evaluated by DPPH and $H_2O_2$ radical and intracellular reactive oxygen species scavenging assays, and it showed moderate activities in all antioxidant assays. Furthermore, loliolide was found to exert positive dose-dependent effects in the protective effects against $H_2O_2$-induced cell damage which were determined via MTT, Hoechst staining assays and cell cycle analysis. This is the first study on chemical constituent of this seaweed according to our best knowledge. These results clearly indicated that loliolide isolated from Sargassum ringgoldianum subsp. coreanum can protect the cells against $H_2O_2$-induced cell damage or apoptosis.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.4
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• pp.771-781
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• 2017

The helmet is an imperative personal protective equipment. This protective device must be able to guard the human head against potential risks. Helmets are classified according into the purpose of use; therefore, the required performance and specifications depend on the type of products. Military helmets are intended to protect the wearer's head from bullets and shrapnel. Generally, lightweight super fibers and fiber reinforced composite materials are used as helmet shell materials, and NIJ STD of U.S. Department of Justice is most widely used as international standard related to bulletproof helmets. Safety helmets are widely used for industrial application and sports leisure. In general, the performance of shock absorption must be ensured, and various lining systems are applied in material, design, and combination methods. Evaluation standards have also been classified and strictly controlled for each purpose; therefore, it is difficult to certify with the existing standards such as the recently developed convergence helmets. However, it is possible to launch the product through a separate national integrated certification procedure.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.33-35
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• 2011

Films of CrAlN and CrZrN were deposited on a steel substrate by closed field unbalanced magnetron sputtering, and their oxidation behaviors were investigated. CrAlN films consisted of dense, polycrystalline CrN and AlN fine columns. The formed oxides consisted primarily of crystalline $Cr_2O_3$ incorporated with $Al_2O_3$. The oxide layers were thin and compact so as to make CrAlN films more protective than CrN films. In case of CrZrN films, Zr atoms were dissolved in the CrN phase. Zr atoms advantageously refined the columnar structure, reduced the surface roughness, and increased the micro-hardness. However, the addition of Zr did not increased oxidation resistance, mainly because Zr was not a protective element. All the deposited films displayed relatively good oxidation resistance, owing to the formation of the highly protective $Cr_2O_3$ on their surface. The $Cr_{40}Zr_9N$ and $Cr_{31}Zr_{16}N$ films oxidized to $Cr_2O_3$ as the major phase and ${\alpha}-ZrO_2$ as the minor one, whereas the CrN film oxidized to $Cr_2O_3$.

• Journal of the Korea Fashion and Costume Design Association
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• v.24 no.4
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• pp.101-116
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• 2022

The purpose of this study is to understand the trends of fashion mask designs as a fashion item with characteristics to protect individual health and safety from harmful environments. To this end, the concept, the trend analysis of the domestic and foreign mask markets, the type, characteristics of functional masks, and the design trend of fashion masks were analyzed. Research methods included case studies and literaturte on mask design, fashion magazines, fashion brand websites, fashion collections, and promotional material. First, masks for personal safety were classified as protective function masks from the natural environment, functional masks by industrial groups, masks for protective functions from biohazards, and masks for protective functions from various external activities. Through this analysis, the design trends of fashion masks were analyzed. The functional orientation of structure and functionality, the environmental orientation of sustainable eco-friendly methods, the fashion orientation of individual fashion styling, and the social functional orientation tend to transmit social messages. In the harmful environment of everyday life, items such as fashion masks with functionality and fashion characteristics should be continuously studied to integrate functional and design characteristics that can contribute to the future fashion industry and the fashion market as a sense of unity and responsibility.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.323-330
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• 2008

The ship collision analysis of steel pile group as protection system of bridge in navigable waterways was performed to analyze the structural characteristics of protective structure during ship collision. The analysis encompassed finite element modeling of ship and pile, modeling of material non-linearity, hard impact analysis, displacement-based analysis and soft impact analysis for collision scenarios. Through the analysis of hard impact with a rigid wall, impact load for each collision type of ship bow was estimated. In the displacement-based analysis the estimate of energy which protection system can absorb within its maximum horizontal clearance so as to secure bridge pier from vessel contact during collision was performed. Soft impact analysis for various collision scenarios was conducted and the collision behaviors of vessel and pile-supported protection system were reviewed for the design of protection system. The understanding of the energy dissipation mechanism of pile supported structure and colliding vessel would give us the optimized design of protective structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.509-514
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• 2001

The Fibre-optic Bragg grating (FBG) sensor is broadly accepted as a structural health monitoring device for Fibre reinforced plastic (FRP) materials by either embedding into or bonding onto the structures. The accuracy of the strain measured by using the FBG sensor is highly dependent on the bonding characteristics among the bare optical fibre, protective coating, adhesive layer and host material. In general, the signal extracted from the embedded FBG sensor should reflect the straining condition of the host structure. This paper presents a theoretical model to evaluate the differential strains between the bare fibre and host material with different adhesive thickness and modulus of the protective coating of the embedded FBG sensor.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1012-1013
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• 2006

A technology of hardening porous materials of titan powders has been elaborated. The technology is based on passing alternating current with duration of ${\sim}10^{-1}{\ldots}10^1$ s through porous ($35{\ldots}40%$) blanks made by method of Sintering by Electric Discharge (SED) by passing a pulse of current with duration of ${\sim}10^{-5}{\ldots}10^{-3}$ s. The influence of technological regimes of porous blanks treatment on their structure and properties is investigated. Geometry and dimension of contact necks between powder particles of obtained samples are evaluated. Variations of porosity and strengths as well as microstructure of porous samples materials before and after treatment are investigated. Optimum range of treatment technological regimes is determined within which porosity of $30{\ldots}35%$ with maximum strength values.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.173-176
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• 2009

We suggest a new protective layer for PDP consists of SrO and MgO double layer. This double layer structure protects SrO layer from the contamination by $H_2O$ or $CO_2$ in the air and enable SrO to play as the main cathode material. It was confirmed that the high secondary electron emission characteristics of SrO by Xe ion can bring considerable driving voltage reduction and improvement of luminance and luminous efficacy in PDP.