• Journal of the Korea Safety Management & Science
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• v.18 no.2
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• pp.19-27
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• 2016

Safety accident rate of small-medium construction site is high. because of lack of safety management system, lack of safety management capacity, lack of investment for safety, Owner's insufficient awareness about safety. In order to improve this, Currently in Occupational Safety and Health Act, Construction site of amounts more than 300 million won less than 120 billion (architectural),150 billion won(civil) mandatory subject to the technical guidance on construction accident prevention. Context of construction accident causes with construction accident rate relationship analysis and case analysis of technical guidance, through a survey of stakeholders in the technical guidance drawn the problems of the construction accident prevention technical guidance system and ways to improve on this.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.176-179
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• 2003

Fuel oxygenates, such as Methyl tertiary Butyl Ether (MTBE) is additive in gasoline used to reduce air pollution. Gasoline components and fuel additives can leak form underground storage tanks. MTBE is far more water soluble than gasoline hydrocarbons like BTEX then it travels at essentially the same velocity as groundwater. MTBE in drinking water causes taste and odor problems. Therefore, the purpose of the this study is to examine the ability of ground rubber to sorb MTBE form water. The study consisted of running both batch and column tests to determine the sorption capacity and the flow through utilization efficiency of ground rubber. The result of Column test indicate that ground tire rubber has on the 36% utilization rate. Finally, it is clear that ground rubber present an attractive and relatively inexpensive sorption medium for a MTBE. The Author thought that to determine the economic costs of ground rubber utilization, the cost to sorb a given mass of contaminant by ground rubber will have to be compared to currently accepted sorption media.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.91-91
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• 1993

The vast number of compounds which have been introduced into our environment in recent years is far beyond our capacity to assess for carcinogenicity using expensive, life-time carcinogenicity studies in rodents. Several in vitro short term assays which are very rapid and inexpensive have therefore been applied as mass screening methods. However, increasing evidence has indicated that mutagenicity results do not always correlate with long-term carcinogenicity. Therefore, the existence of discrepancies dictates the necessity of suitable in vivo rapid assay systems which could bridge the gap between mutagenicity and conventional long-term testing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.292-295
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• 2006

Dimension and capacity of the zero tail type mini excavator are small as compared with medium or large excavators. Therefore, problems of the noise and the heat are major issues in design due to layout of each component such as the engine and the hydraulic module. It is necessary to reduce the noise and the vibration of construction machine, due to be enforced regulation for high noise construction machinery in the world. The objective of this study is to provide basic data which is apply to predict noise effect in detail design stage by estimating noise of cabin for zero tail type mini excavator.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.529-529
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• 2012

Dispersion of carbon nanotubes in biocompatible media are of particular interest for diverse biomedical and nanomedicine applications. Various biomolecules and biopolymers such as DNA, proteins, poly L-lysine, starch, gelatin, steroid biosurfactants, and chitosan have shown capability for the effective dispersion of carbon nanotubes in water. Chitosan has demonstrated capacity for effective dispersion of single-walled carbon nanotubes (SWCNTs) in acidic medium and it also showed tendency to preferentially disperse smaller diameter nanotubes. Chemical functionalizations of chitosan enable its solubility in neutral pH water by reducing the intra and inter molecular hydrogen bonding. Herein, we present a neutral pH water soluble chitosan derivative, chitosan-hydroxyphenyl acetamide (CHPA), obtained by functionalizing the amino groups of chitosan with 4-hydroxyphenyl acetic acid, as an efficient biocompatible dispersant for debundling and solubilization of SWNTs in neutral aqueous solutions. Various process conditions for individual dispersion of SWCNTs are analyzed based on optical absorption and Raman spectroscopy.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.101-112
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• 2015

Renewable energy resources play an important part in the world's future. Renewable energy sources have the following components: biomass, geothermal, solar thermal, directs solar, wind, tidal and hydropower. Hydropower is still the most efficient way to generate electricity worldwide. Hydropower projects can contribute as a cheap energy source, as well to encourage the development of small industries across a wide range of new technology; furthermore hydropower systems use the energy in flowing and falling water to produce electricity or mechanical energy. Hydropower systems are classified as large, medium, small, mini and micro according to their installed power generation capacity, as do the following components: water turbines, control mechanisms and electrical transmissions. In this article a review of small hydropower systems has been done on the principles surrounding the fundamentals of hydraulic engineering, the fundamentals of hydrology, identification of sites and economic analysis.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.347-351
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• 2004

The cryogenic test facility is developed for test of deep groove ball bearings, floating ring seals, materials (steel & copper) for High Pressure Turbopump of liquid rocket engine (LRE). The cryogenic bearing test is performed to evaluate the flow rate of cooling water and the load-carrying capacity of bearings. The cryogenic seal test is performed to evaluate the determination of magnitude of leakages through the seal, a time variation of this magnitude. The test of the materials Pair is performed to evaluate its fitness for operation in the liquid oxygen medium.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.93-99
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• 1996

In this study, we compare performance of priority schemes of FDDI and Expressnet for integrated voice and data traffic through simulation. The voice capacity of FDDI is higher than that of Expressnet for all cases considered. When compared to Expressnet, FDDI achieves a higher data throughput for file transfer traffic but it incurs a longer delay for interactive traffic.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.214-219
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• 2008

In this study, medium capacity EHP and GHP for air-conditioning a building with a floor area of $1,200\;m^2$ are compared economically. To consider all the factors of initial and operation costs effectively, an annual equal payment method is proposed. For the initial cost, equipment, construction, installation, electric facility, financial subsidy and tax cut are considered. Basic electricity, energy(electricity and gas), space charge, labor, insurance and repair are considered for the operation cost. Under the assumptions made in this study, overall cost of EHP is less than that of GHP. However, different outcome may result if different assumptions are made. This study is useful for performing an economic evaluation of various air-conditioning systems.

• Journal of Ginseng Research
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• v.5 no.1
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• pp.35-40
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• 1981

Explants of mature root tissues and calli derived from root and cotyledon of Panax ginseng were cultured in vitro on Murashige and Skoog medium supplemented with 2, 4-dichlorophen-oxyacetic acid(3,4-D), naphthaleneacetic acid(NAA), benzyladenine, and gibberellic acid to assess their capacity to regenerate organs. Root formation at high percentage (46.2-61.1%) was obtained 20-30 days after culturing on media supplemented with combinations of NAA(5 mg/l) and kinetin (1 mg/l), And calli derived from cotyledon produced numerous embryoids in media($\frac{1}{2}$MS) containing 2,4-D(0.5 mg/l) and kinetin (0.5 mg/l). Reculture of these embryoids in media($\frac{1}{2}$MS) enriched with 1 mg/l of benzyladenine and 1 mg/l of gibberellic acid resulted in more plantlet regeneration.