• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.3
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• pp.63-82
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• 2022

The purpose of this study is to compare growth condition of landscape woody plants growing on the different ground structures in apartment complex. I chose Manseok Beach Town Complex 2, in Manseok-dong, Seo-gu, Incheon which has both natural and artificial ground as a subject site. Analysis of three phases of soil showed that artificial ground had average liquid phase of 30.89%, artificial ground mounding 33.88% and natural ground 24.40%. It means that artificial ground has higher water content than natural ground despite having same earthiness. It is believed that artificial ground is not as well drained as natural ground even though it is connected to the natural ground and has a deep soil depth because of mounding. Comparative study between woody plants on natural ground and those on artificial ground demonstrated that trees on natural ground grew 40.4% compared to those on artificial ground(0.875mm more) in terms of diameter growth. Average diameter growth of trees on natural ground was 3.040mm against 2.165mm for those on artificial ground. All 19 tree species which were measured for root diameter growth showed similar or higher growth on natural ground than on artificial ground. When it comes to growth of height, arborvitae showed highest growth on natural ground, followed by Thuja occidentalis, Pinus strobus, Magnolia denudata, Diospyros kaki and Aesculus turbinata. I measured branch growth and rate of leaf adherence of Pinus strobus. Average annual rate of branch growth of woody plants on natural ground was twice as high as those on artificial ground. I could conclude that ground structure influences branch growth of Pinus strobus. Statistics analysis of tree damage demonstrated significant result, meaning that there is a difference in the average damage rate depending on structure of ground. In order to validate growth difference by planting ground, I conducted T-Test of growth of diameter, root diameter, branch and height on woody plants growing on natural and artificial ground. As a result, it is believed that there is a difference in the growth of trees depending on the ground structure. Putting all these results together demonstrates that woody plants on natural ground generally grow better than those on artificial ground, which means ground structure does have an influence on the environment of growth of trees.

• Journal of Korean Society of Steel Construction
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• v.15 no.2
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• pp.117-124
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• 2003

Wind-induced motions, like acceleration for instance, often influence designs for high-rise buildings. As a consequence, correct assessment of natural frequency becomes important. The empirical expressions used to quantify this parameter at the design phase tend to yield values that are significantly different from each other. This paper is concerned with the natural periods of steel buildings. It describes the vibration measurement methods that were employed for testing buildings. This paper will also present reliable methods of assessing the natural period from ambient vibration tests. Data from measurements on 21 buildings in Seoul were provided while 21 buildings were tested by ambient vibration measurements to obtain the natural periods. While regression formulas of natural periods for steel-frarried tall buildings were suggested,the obtained formula was compared with the empirical expressions of structural standards and the Eigen-value analysis.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2107-2110
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• 2009

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.6
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• pp.73-81
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• 2006

A commercial diesel engine was converted into a dedicated natural gas engine to reduce the exhaust emissions in a retrofit of a diesel-fueled vehicle. The cylinder head and piston were remodeled into engine parts suited for a spark ignition engine using natural gas. The remodeling of the combustion chamber changed the compression ratio from 21.5 to 10.5. A multi-point port injection(MPI) system for a dedicated natural gas engine was also adopted to increase the engine power and torque through improved volumetric efficiency, to allow a rapid engine response to changes in throttle position, and to control the precise equivalence ratio during cold-start and engine warm-up. The performance and exhaust emissions of the retrofitted natural gas engine after remodeling a diesel engine are investigated. The emissions of the retrofitted natural gas engine were low enough to satisfy the limits for a transitional low emission vehicle(TLEV) in Korea. We concluded that a diesel engine can be effectively converted into a dedicated natural gas engine without any deterioration in engine performance or exhaust emissions.

• International Journal of Automotive Technology
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• v.6 no.6
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• pp.579-584
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• 2005

Unsteady state free natural gas jets injected from several types of injectors were numerically simulated. Simulations showed good agreements with the schlieren experimental results. Moreover, injections of natural gas in intake manifolds of a single-valve engine and a double-valve engine were predicted as well. Predictions revealed that large volumetric injections of natural gas in intake manifolds led to strong impingement of natural gas with the intake valves, which as a result, gave rise to pronounced backward reflection of natural gas towards the inlets of intake manifolds, together with significant increase in pressure in intake manifold. Based on our simulations, we speculated that for engines with short intake manifolds, reflections of the mixture of natural gas and air were likely to approach the inlets of intake manifolds and subsequently be inbreathed into other cylinders, resulting in non-uniform mixture distributions between the cylinders. For engines with long intake manifolds, inasmuch as the degrees of intake interferences between the cylinders were not identical in light of the ignition sequences, non-uniform intake charge distributions between the cylinders would occur.

• Natural Product Sciences
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• v.23 no.2
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• pp.139-145
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• 2017

Seven flavonoid compounds, kaempferol (1), quercetin (2), quercetin-3-O-${\beta}$-D-glucopyranoside (3), kaempferol-3-O-${\beta}$-D-glucopyranoside (4), kaempferol-3-O-${\alpha}$-L-rhamnoside (5), quercetin-3-O-sophoroside (6) and quercetin-3-O-rutinoside (7), were isolated from the methanolic extract of leaves of Kalanchoe prolifera. Compounds 1-7 were isolated for first time from this plant. These compounds were evaluated their cytotoxic activity against P-388 murine leukimia cells in vitro. Among those compounds kaempferol (1) and quercetin (2) showed strongest cytotoxic activity with $IC_{50}$ values of $4.45{\pm}0.05$ and $6.28{\pm}0.02{\mu}g/mL$, respectively.

• Journal of the Korea Fashion and Costume Design Association
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• v.1 no.1
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• pp.53-71
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• 1999

The purpose of this study is to determine the fashion images implied in men's fashion trends and systematize the characteristics of the textile materials used for fashion images, by analyzing men's fashion trends published by Korean fashion information service companies. This study would be meaningful if it can suggest some objective criteria for the characteristics of textile per fashion image. The researcher analyzed the data on the basis of 8 fashion images, which were ethnic, modern, traditional, avant-garde, active, romantic, natural, techno ones. Above men's fashion images were choosed by analyze the some literatures and men's fashion trend information. The data used for this study were information about S/S and F/W men's fashion trends published by Interfashion planning, Samsung fashion Research Center for the period of 1995-2000. The data collected were subject to “content analysis method”. As a result of the analysis, the major images of 1995-2000 were natural, active, traditional, modern, ethnic, avant-garde, techno images, and while such combinations of conflicting images as ethnic/modern, traditional/avant-garde, natural/techno. Other mixed images were ethnic/natural, modern/active, tradional/active, traditional/modern, romantic/modern, ethnic/romantic, traditional/natural, modern/natural, active/natural, active/traditional/natural, etc. The various characteristics of eight men's fashion images were found in color, pattern and textile materials.

• New & Renewable Energy
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• v.2 no.2 s.6
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• pp.94-101
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• 2006

[ $1m^3$ ] solid hydrate contains up to $200m^3$ of natural gas, depending on pressure and temperature. Such large volume of natural gas hydrate can be utilized to store and transport large quantity of natural gas in a stable condition. So, in the present investigation, experiments carried out for the formation of natural gas hydrate governed by pressure, temperature, and gas compositions, etc.. The results show that the equilibrium pressure of structure II natural gas hydrate) is approximately 65% lower and the solubility is approximately three times higher than structure I methane hydrate). Also, the subcooling conditions of the structure I and II must be above 9K and 11K in order to form hydrate rapidly regardless of gas components, but the pressure increase is more advantageous than the temperature decrease in order to increase the gas consumption. And utilizing nozzles for spraying water in the form of droplets into the natural gas dramatically reduces the hydrate formation time and increases its solubility at the same time.

• Analytical Science and Technology
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• v.18 no.1
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• pp.89-95
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• 2005

Studies on the electrochemical reduction of 7-acetoxy-4-bromomethyl-coumarin (ABMC), 7-acetoxymethyl coumarin (AMC), and coumarin in 0.1 M tetraethyl ammonium perchlorate acetonitrile solution were carried out with direct current, differential pulse polarography, cyclic voltammetry, and controlled potential coulometry. The electrochemical reduction of ABMC was proceeded through three irreversible steps coupled with the chemical reactions. The solution color was changed to yellow when the carbonyl group was reduced during second step and the color change was independent with bromo group of ABMC. Fluorescent intensity was highest when the electrochemical reduction was controlled at near the overpotential of supporting electrolyte (-2.3 volts).

• Korean Institute of Interior Design Journal
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• no.13
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• pp.130-138
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• 1997

This study is to present the visual phenomenon of natural light in the interior space. The continuously changing natural light define the visual phenomenon of the architectural space. First, the objective of this study was finding the importance of the visual phenomena which were generated from correlating natural right with the interior space. And the second was to categorize the factors of the visual phenomenon which can be useful factors for modern interior design practice. As a result of this study, two visual phenomena were classified. First; territorial phenomenon: dividing, partitioning, and sectioning by natural light, Second; phenomena by the inflow methods of natural light; a) by direct inflow; transparency, expansion, and floating, b) by filtering fixtures; the architectural structure, color, and the transluscent material, c) by dramatic spacial present of natural light, d) by the sense of direction of naturel light; continuity, and transformatiov. Found and classified each factor is not presented by itself, rather compounded forms. Because of the limited analysis of modern buildings, these found visual factors can not represent all phenomena. But if we practice these finding factors to design present interior space, it is sure of being very valuable factors to re-introduce the overlooked natural light into interior space.