• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.33-39
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• 2016

Color image dehazing techniques have been extensively studied, and especially the dark channel prior (DCP)-based method has been widely used. Near infrared (NIR) image based applications are also widespread; however, NIR image-specific dehazing techniques have not attracted great interest. In this paper, the characteristics of NIR images are analyzed and compared with the color images' characteristics. The conventional color image dehazing method is also applied to NIR images to understand its effectiveness on different frequency-band signals. Furthermore, we modify the DCP method considering the characteristics of NIR images and show that our proposed method results in improved dehazed NIR images.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.219-222
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• 1998

In this study, The water tree characteristics were investigated when crosslinking coagent was added in XLPE/EnBA blends. When XLPE was blended with EnBA, there was a decrease of water tree length as an increase of nBA contents in XLPE/EnBA20 blends. The effect of crosslinking coagent. A was better than those of other crosslinking coagents B, C and D in water tree retardation. In case of XLPE/EnBA/Crosslinking coagent blends, water tree length was increased as the crosslinking coagents were increased from 0.2 to 2 phr in 2.0 phr DCP content. To clarify the effects of crosslinking coagent, the DCP contents were changed from 1.5 to 2.0 par in the same crosslinking coagent contents. Then, there was a decrease of water tree length as an increase of crosslinking coagent contents in 1.5 and 1.8 phr DCP contents.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.3
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• pp.10-21
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• 2021

Recently, the demand for atypical structures with functions and sculptural beauty is increasing in the construction industry. Existing mold-based structure production methods have many advantages, but building complex atypical structures represents limitations due to the cost and technical characteristics. Production methods using molding are suitable for mass production systems, but production cost, construction period, construction cost, and environmental pollution can occur in small quantity batch production. The recent trend in the construction industry calls for new construction methods of customized small quantity batch production methods that can produce various types of sophisticated structures. In addition to the economic effects of developing related technologies of 3D Concrete Printers (3DCP), it can enhance national image through the image of future technology, the international status of the construction civil engineering industry, self-reliance, and technology export. Until now, 3DCP technology has been carried out in producing and utilizing residential houses, structures, etc., on land or manufacturing on land and installing them underwater. The final purpose of this research project is to produce marine structures by directly printing various marine structures underwater with 3DCP equipment. Compared to current underwater structure construction techniques, constructing structures directly underwater using 3DCP equipment has the following advantages: 1) cost reduction effects: 2) reduction of construct time, 3) ease of manufacturing amorphous underwater structures, 4) disaster prevention effects. The core element technology of the 3DCP equipment is to extrude the transferred composite materials at a constant quantitative speed and control the printing flow of the materials smoothly while printing the output. In this study, the extruding module of the 3DCP equipment operates underwater while developing an extruding module that can control the printing flow of the material while extruding it at a constant quantitative speed and minimizing the external force that can occur during underwater printing. The research on the development of 3DCP equipment for printing concrete structures underwater and the preliminary experiment of printing concrete structures using high viscosity low-flow concrete composite materials is explained.

• The Korean Journal of Food And Nutrition
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• v.36 no.1
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• pp.6-16
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• 2023

To investigate the anti-inflammatory activity of submerged culture using Cordyceps militaris mycelium, culture-including mycelia was extracted and lyophilized into postbiotics (hot-water extract; CM-HW). HW was fractionated into crude polysaccharide (CM-CP) by ethanol precipitation, and CM-CP was further dialyzed into CM-DCP by dialysis with running water using 12~14 kDa dialysis tube. When the cytotoxicity of subfractions against cells was assessed, no subfraction had a cytotoxic impact that was substantially different from the control groups. In an inflammatory model using LPS-stimulated RAW 264.7 cells, CM-DCP significantly decreased IL-6 and MCP-1 production levels compared to the LPS-control group. CM-DCP also inhibited IL-6 and IL-8 secretion in HaCaT keratinocytes stimulated with TNF-α and IFN-γ. In the meanwhile, the neutral sugar content and mannose ratio of anti-inflammatory CM-DCP were higher than the other fractions, and CM-DCP contained β-1,3/1,6-glucan of 216.1 mg/g. High pressure size exclusion chromatography revealed that CM-DCP contained molecules with a molecular weight range of 5.6 to 144.0 kDa. In conclusion, postbiotics of C. militaris mycelium significantly promoted anti-inflammatory activity, suggesting that neutral polysaccharides including Glc and Man contribute to the anti-inflammation in RAW 264.7 or HaCaT cells.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.34 no.3
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• pp.262-278
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• 2024

Objectives: To investigate the work environment measurement (WEM) status and concentration levels of substances with short-term exposure limits (STEL) among special management substances. Methods: Data from the past 5 years of WEM for 6 substances (1,2-dichloropropane (1,2-DCP), 1,3-butadiene, benzene, trichloroethylene (TCE), perchloroethylene (PCE) and sulfuric acid) were analyzed. The number of samples and concentration level of STEL and 8-hour TWA (time weighted average) were compared. Results: The number of STEL measurement for 1,3-butadiene, benzene, and sulfuric acid was less than 1% of the number of TWA measurement samples, while TCE, 1,2-DCP, and PCE, which are mainly used for cleaning metals, were relatively high, at 16.1%, 5.6%, and 2.2%, respectively. When comparing the concentrations of STEL with TWA on the same STEL measured workers (STEL-matched TWA), STEL concentrations were 2.8, 3.1, 2.6, 2.6 and 40.5 times higher than TWA as 1,2-DCP, benzene, TCE, PCE, and sulfuric acid. When comparing the concentration of STEL-matched TWA with the total TWA, STEL-matched TWA was 3.4, 8, 1.4, 2.0, 8.6 and 0.7 times higher for 1,2-DCP, benzene, 1,3-butadiene, TCE, PCE, and sulfuric acid, respectively. Conclusions: This study found that the workers performing irregular tasks may be exposed to higher concentrations of hazardous substances than regular workers. It is necessary to strengthen short-term exposure measurement, even for substances which STEL have not been set.

• Journal of the Korean Geotechnical Society
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• v.31 no.3
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• pp.63-72
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• 2015

This paper describes the correlation and relationship between elastic moduli measured by three stiffness measurement methods with different mechanical characteristics to evaluate the compaction characteristics of subgrade soils. The Soil Stiffness Gauge (SSG) with very small strain (${\approx}0.001%$) ranges, static Plate Loading Test (PLT) with mid-level strain (${\approx}0.01{\sim}0.1%$) ranges, and Dynamic Cone Penetrometer (DCP) using penetration resistance were implemented to measure the elastic modulus. To use the elastic modulus measured by different measurement methods with a wide range of strain in practice, it is required to identify the correlation and relationship of measured values in advance. The comparison results of the measured elastic moduli ($E_{SSG}$, $E_{PLT}$, $E_{DCP}$) using the three measurement methods for domestic and overseas subgrade soils under various conditions indicate that the evaluated elastic modulus relies on the types of soils and the level of stress condition. The correlation analysis of the measured elastic moduli except the data of cement treated soils indicates that the static elastic modulus ($E_{PLT}$) is evaluated as about 60 to 80% of the dynamic elastic modulus ($E_{SSG}$). Unusual soils such as cement treated soils are required to be corrected by the stress correction during the correlation analysis with typical soils, because these types of soils are sensitive to the stress condition when measuring the static elastic modulus ($E_{PLT}$) of soils. In addition, when considering the use of DCP data for the evaluation of the elastic modulus ($E_{DCP}$), the measured data of the elastic modulus less than 200 MPa show more reliable correlation.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.63-72
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• 2024

Poly (butylene adipate-co-terephthalate) (PBAT) is one of the representative biodegradable polymers with high ductility and processability to replace petroleum-based polymers. Many investigations have been conducted to broaden the applications of PBAT in a variety of industries, including the food packaging, agricultural mulching film, and logistics and distribution fields. Foaming process is widely known technique to generate the cell structure within the polymer matrix, offering the insulation and light weight properties. However, there was no commercially feasible foam product based on biodegradable polymers, especially PBAT, and maintaining a proper melt viscosity of the polymer would be a key parameter for the foaming process. In this study, chemical foaming agent and cross-linking agent were introduced to PBAT, and a compression molding process was applied to prepare a foam sheet. The correlation between cell morphological structures and mechanical and physical properties was evaluated. It was found that PBAT with foam structures effectively reduced the density and thermal conductivity, allowing them to be suitable for applications such as insulation and lightweight packaging or cushion materials.

• Proceedings of the Korea Contents Association Conference
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• 2006.11a
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• pp.52-57
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• 2006

This research studies and analyzes the current trends and the frequency allocation bands for digital cordless phone(DCP) in other county. From these results, we propose 1.7GHz & 2.4GHz as a effective candidate frequency band for domestic DCP. A proposed 1.7GHz is expected to introduce DECT system of Europe. Therefore it is necessary to make an analysis of interference between 1.7GHz band and an adjacent IMT-2000 band. In this paper, we proposed the allocation of channel for 1.7GHz on the basis of the analysis of frequency interference between 1.7GHz band and an adjacent IMT-2000 band.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1992-1994
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• 1999

Dicumyl peroxide (DCP) is used for crosslinking agent in general. And the correlation between polyethylene and DCP is significant in particular radiation environment. On this paper, The effects on $Co^{60}{\gamma}$-ray irradiation of polyethylene doped dicumyl peroxide(DCP) were investigated. We experimented on electrical properties as following; electrical tree inception and growing type for applying AC step voltage, AC breakdown strength, volume resistivity, capacitance and dissipation factor at high frequency as increasing dosage. Also, chemical analysis was performed TGA, gel content.

• Journal of The Korean Astronomical Society
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• v.26 no.2
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• pp.135-139
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• 1993

Events of eclipses as well as other major astronomical events observable in the eastern sector of Asian continent are computed and checked with astronomical records of antiquity. Particular attention was given to two types of the events recorded in remaining records of Dangun Chosun Period (DCP): (1) concentration of major planets near the constellation of Nu-Sung $(\beta\;Aries)$ and (2) a large ebb-tide. We find them most likely to have occurred in real time. i.e., when the positions of the sun, moon, and planets happen to be aligned in the most appropriate position. For solar eclipses data, however, we find among 10 solar eclipse events recorded, only 6 of them are correct up to months, implying its statistical significance is no less insignificant. We therefore conclude that the remaining history books of DCP indeed contains important astronomical records, thereby the real antiquity of the records of DCP cannot be disproved.