• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.209-210
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• 2019

This paper investigates and analyzes related systems, policies, and research trends that are used to prepare the operating regulations for drone-based fine dust monitoring and water fog injection systems in small-sized construction site. As a result of the study, we have drawn a total of six major items to consider when drafting the drone related operational regulations. It will also be used as a basis for future development system operation regulations.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.140-147
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• 2018

The performance of a hydrate anti-agglomerant (AA) on cyclopentane (CyC5) hydrate anti-agglomeration at various concentrations (0-1 wt%, based on the oil phase) using MMF apparatus has been investigated. At low AA concentrations up to 0.01 wt%, the AA reduces the cohesion force (capillary force) by reducing the CyC5-water interfacial tension. At concentrations higher than 0.1 wt%, hydrate hydrophobicity alternation and AA's thermodynamic inhibition effects are the main part of AA's mechanism. Additionally, a "temporary agglomeration" phenomenon caused by surface melting of the hydrate particles is also observed, which may indicate the AA's weak ability to produce stable water-CyC5 interface.

• Journal of the Korea Institute of Building Construction
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• v.12 no.1
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• pp.64-72
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• 2012

Recently, prepackaged-type surface preparation materials using redispersible polymer powders are widely used for interior and exterior finishing in the construction work. The purpose of this study is to evaluate the performance and the quality of prepackaged-type surface preparation materials using a VA/E/MMA terpolymer powder. Surface preparation materials using a VA/E/MMA terpolymer powder were prepared with shrinkage reducing agent contents of 0, 4 % and cellulose fiber contents of 0, 0.5, 1.0 %, and tested for drying shrinkage, strengths, adhesion in tension, crack and impact resistance, water absorption, permeability. As a result, prepackaged-type surface preparation materials show outstanding performance depending on the shrinkage reducing agent and cellulose fiber contents.

• Journal of Applied Biological Chemistry
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• v.51 no.3
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• pp.111-116
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• 2008

Aralia elata seeds were successively extracted with water, methanol, ethanol, acetone and chloroform. The crude extracts were investigated for antioxidant and antidiabetic activities. The antioxidant properties of various extracts were evaluated by antioxidant tests, such as DPPH free radical-scavenging activity, hydroxyl radical-scavenging assay, metal-chelating activity, lipid peroxidation inhibition activity and reducing power assay. The 70% methanol extract exhibited the highest activity in the in vitro models of DPPH free radical-scavenging activity, metal-chelating activity, and reducing power assay. Acetone extract showed good effects on lipid peroxidation inhibition and hydroxyl radical-scavenging assay at a low concentration. In addition, the $\alpha$-glucosidase inhibition assay showed that 70% methanol extract had the highest activity. These results indicate the high possibility of using A. elata seeds for medical application due to their efficient antioxidant properties.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.297-300
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• 1998

Usually the flowing concrete manufactured upon normal-mixed base concrete would segregate due to the less of fine particle content. In the previous studies, a new type admixture(liquid segregation reducing type superplasticizer) has been developed to prevent such segregation without modification of base concrete mixture. In this study, the tests are performed in laboratory to evaluate the admixture by analyzing the properties of flowing concrete with different water to cement ratios, so that it could be used in the fields. According to the results, this kind of superplasticizer could improve the fluidity of concrete without causing segregation. However, it seems to be more desirable of the superplasticizer could be adjusted, before it is put into the practical use, not to cause some other problems such as rapid rate of slump and air loss and retarding of setting time.

• Korean Journal of Pharmacognosy
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• v.38 no.2 s.149
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• pp.152-156
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• 2007

Protein-bound polysaccharide is derived from Acanthopananx senticosus by the cold water extraction. The aim of the study was to evaluate the effects of PS against weight loss and hematological change as a indication of toxicity produced by the treatment of cisplatin. PS protected the weight loss caused by cisplatin (6 mg/kg) and significantly recovered hematological change. Treatment of PS showed the recovery on the weight loss and hematological change as indicators of toxicity of cisplatin treatment. By increasing lymphocyte proliferation and cytokine production, PS may be highly effective in protecting against cisplatin-induced toxicity. The results suggest PS might have a role in reducing toxicity or permitting larger dose of cisplatin to be given.

• Korean Journal of Environmental Biology
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• v.21 no.4
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• pp.377-383
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• 2003

The functional Jeungpyuns with dietary fiber containing cereals such as brown rice and barley flour were developed and physiochemical properties were investigated. The water binding capacity had significantly the highest value of 28.4% in raw rice flour, followed by brown rice flour and barley flour. The lowest reducing sugar value was seen in unpolished rice substituted Jeungpyun with value of 5.420 (P<0.05). The amount of reducing sugar decreased slightly after steaming, due to the increased degree of sugar dissociation. The L value of the lightness decreased significantly with the substituted samples (P< 0.05). The barley substituted samples were darker than that of brown rice sample groups with less green and yellow color. Microstructures of starch particles after fermentation showed completely dispersed starch particles with air bubbles and sponge-like structure in all samples after steaming. Thus, functional Jeungpyun replaced with brown rice and barley flour can be successfully formulated and has been influenced by the physicochemical properties.

• Ocean Systems Engineering
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• v.2 no.1
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• pp.69-81
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• 2012

Presented herein is a study on reducing the hydroelastic response of very large floating structures (VLFS) by altering their plan shapes. Two different categories of VLFS geometries are considered. The first category comprises longish VLFSs with different fore/aft end shapes but keeping their aspect ratios constant. The second category comprises various polygonal VLFS plan shapes that are confined within a square boundary or a circle. For the hydroelastic analysis, the water is modeled as an ideal fluid and its motion is assumed to be irrotational so that a velocity potential exists. The VLFS is modeled as a plate by adopting the Mindlin plate theory. The VLFS is assumed to be placed in a channel or river so that only the head sea condition is considered. The results show that the hydroleastic response of the VLFS could be significantly reduced by altering its plan shape.

• Geomechanics and Engineering
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• v.12 no.1
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• pp.71-83
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• 2017

Collapsible soil presents a porous unsaturated structure, its sudden settlement after humidification, without supplementary charge, can be of a big nuisance for the foundations and therefore for the constructions built on it. To improve its structure and limit its instability, samples of laboratory reconstituted soil, with different percentages of water contents and compacted at different compaction energies, were treated with glass-fiber. The study of the mechanical behavior was performed by oedometer tests. The microstructure was explored by the Scanning Electron Microscope (SEM). The results obtained show clearly the efficiency of the treatment with glass fiber on reducing the collapsibility of such soil.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.175-180
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• 1999

The heating system of korea apartment house is called Ondol. The surface finishing mortar of this floor system typically used the cement based mortar, where the surface finishing mortar easily appears the crack. To order to crack control, the cement that added expansive additive used to reducing dry-shrinkage. For the surface finishing mortar, the types of shrinkage is known as plastic shrinkage, dry-shrinkage and autogenous This experimental study is to investigate the difference on dry-shrinkage of the cement that added expansive additives and OPC. The test method is varied the ration of water/cement (W/C) and the ratio of sand/cement(S/C). For OPC, The increase of the ratio of S/C is reduced dry-shirnkage but for the cement that added expansive additives, the increase of the ratio of S/C is augmented dry-shrinkage For OPC, The increase of the ratio of W/C is augmented dry-shrinkage but for the cement that added expensive, the increased of the ratio of W/C is reduced dry-shrinkage.