• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.52-56
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• 2001

Experiments of 2 type on insulating compounds accomplished to change PVC using in URD(Underground) power cable jacketing. one was DB(Dielectric Breakdown) test on the pure base resins and the others were WVT(Water Vapor Transmission) test on the compounds which contained C/B(Carbon Black), anti-oxidant to base resin. a kind of specimens made by pressing to resin of pellet or lump form was HDPE(High Density Polyethylene), MDPE(Medium Density Polyehylene), LDPE(Low Density Polyethylene), LLDPE(Linear Low Density Polyethylene), PVC(Polyvinyl Chloride). As a results of AC DB and WVT test, we saw that strength of Insulation was HDPE> LLDPE = MDP E> LDPE and WVT ratio was HDPE

• Journal of the Korean institute of surface engineering
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• v.41 no.2
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• pp.63-68
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• 2008

Traditionally and generally used calcined clay was carburized, and its characteristics were studied. Carburization treatment was performed by the thermally decomposed carbon and the deposit carbon which occur in a so called 'Boudouard reaction $(2CO{\rightarrow}CO_2+C)'$ at fuel combustion process in a closed-type furnace. The color of the carburized calcine clay changed from yellow to black, and the carbon component revealed as crystalline graphite by the X-ray diffraction test. The weight of the carburized calcine clay decreased to about 4 wt.% by the 1st heating to $1400^{\circ}C$ in air but it does not decreased by the 2nd heating of the same conditions. By the carburization treatment, the water absorption changed from 13 wt.% to 6 wt.%, and the contact angle for water drop changed, too, from 0 to $87^{\circ}$ which was tested by the photograph of one minute after a water drop contact. It means the carburized calcine clay does not absorb water drop so it has a hydrophobic characteristic.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.9
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• pp.1020-1025
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• 2012

In this study, we fabricated the superhydrophobic and super-water-repellent surface with the micro/nano scale structures using simple conventional silicon wet-etching technique and the black silicon method by deep reactive ion etching. These fabrication methods are simple but very effective. Also we reported the droplet impact experimental results on the micro/nano-scaled surface. There are two representative impact behaviors as "rebound" and "fragmentation". We found the transition Weber number between "rebound" and "fragmentation" statements, experimentally. Additionally, we concerned about the dimensionless spreading diameters for our super-water-repellent surface. The novel characterization method was introduced for analysis including the "fragmentation" region. As a result, our super-water-repellent surface with the micro/nano-scaled structures shows the different impact behaviors compared with a reference smooth surface, by some meaningful experiments.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.615-625
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• 2015

This study examined the effects of wildlife or wildlife species on national park visitors' perception of place attributes and recreational experiences. Data were collected from 502 users of Seongsamjae Rest area and Nogodan Shelter area in Jirisan National Park and 173 college students during May-June 2014 using survey questionnaire. Some simulated photographs of water deer and Asiatic black bears were used for the college student survey. Overall, awareness about wildlife inhabiting in Jirisan National Park (AW) was not related with one's perception of place attributes (PPA) (i.e., crowdedness, naturalness, safety) and types of visitors' recreational experiences. Respondents with higher awareness about the presence of Asiatic black bear (AABB), however, tended to perceive Jirisan National Park as a place that provides 'wild' or 'natural' recreational opportunities compared to those with lower AABB. Differences in PPA (i.e., crowdedness, naturalness, safety) and types of recreational experiences were also found to be influenced by wildlife species. Respondents exposed to bear or water deer tended to perceive their recreational experiences as more 'wild'. Existence of wildlife in Jirisan National Park had a positive effect on the quality of visitors' recreational experiences. Different wildlife species showed different levels of effectiveness to quality enhancement of recreational experience. Some practical implications of the study were discussed from a managerial point of view.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.504-510
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• 2015

This study was carried out to investigate the antioxidant effects of different parts (stems, leaves, and seeds) of the black raspberry for utilization as food materials. Different parts of the black raspberry were subjected to extraction via ultra-sonication extraction methods using water and ethanol at various concentrations (25, 50, 75, and 100%). Antioxidant capability of the extracts were determined by amounts of phenolic compounds, with flavonoid contents, radical scavenging activity, and reducing power. Irrespectively of ethanol concentration, extracts of stem showed the highest total phenolic compounds and antioxidant activities among different parts of black raspberry. The total phenolic compounds extracted from the black raspberry stem using 25 and 50% ethanol showed $348.21{\pm}5.40$ and $343.39{\pm}5.94mg/g$, respectively. Fifty percent ethanol extracts of the black raspberry stem showed the highest DPPH ($EC_{50}$ value: $60.89{\mu}g/mL$) and ABTS radical scavenging activities ($EC_{50}$ value: $82.57{\mu}g/mL$). Further, 25% ethanol extacts of the black raspberry stem ($0.263{\pm}0.004$) was found to have the highest reducing power. The highest antioxidant activity of black raspberry stem indicates that black raspberry stem may be useful source for functional food.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.4
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• pp.497-505
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• 2012

The nutritional, physicochemical and sensory quality characteristics of chilled loins of Jeju Black Cattle, Hanwoo and imported Australian beef were compared. For nutritional properties, moisture and crude protein contents of Jeju Black Cattle beef were 65.91% and 17.39% respectively, the lowest among the comparison groups. On the other hand, their crude fat and crude ash contents were 15.89% and 0.79%, respectively, the highest among the comparison groups. There was a significant difference in crude ash content, but there was no significant difference in the other properties. The Fe and Zn contents of Jeju Black Cattle beef were 29.85 and 48.13 ppm, respectively, lower than those of Hanwoo beef, although the difference was not significant. These values were higher than those of Australian beef (p<0.05). There was no significant difference among the samples in contents of Ca, P, Na and Cu. The total amino acid and essential amino acid contents of Jeju Black Cattle beef were 16.81% and 9.08%, respectively, the lowest among the samples, although the difference was not significant. The ratio of essential amino acids to total amino acids of Jeju Black Cattle beef was 54.01%, the highest among the samples. The saturated fatty acid (43.25%), stearic acid (13.51%), linoleic acid (2.39%) and essential fatty acid (2.47%) contents of Jeju Black Cattle beef were the lowest. However, their unsaturated fatty acid (56.69%), oleic acid (47.80%) and MUFA/SFA ratios were the highest, and there were significant differences compared with Australian beef. There was no significant difference in the PUFA/SFA ratio. Among physicochemical properties, redness ($a^*$) of Jeju Black Cattle beef was the highest while melting point was the lowest (p<0.05). There were no significant differences in lightness ($L^*$), yellowness ($b^*$), pH, water holding capacity, cooking loss or shear force value. For sensory properties, raw meat aroma, cooked meat aroma and palatability of Jeju Black Cattle beef were superior compared to other comparison groups, with significant differences in comparison with Australian beef (p<0.05). However, there were no significant differences in taste, juiciness, or tenderness of cooked meat.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.43-48
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• 2003

Black liquor staining for the development of natural color of bleached Hanji caused problems of discoloration and degradation. This study was carried out not only to complement these problems but also to develop natural dyeing method that was similar to the color of unbleached Hanji, through the dyeing of rice straw extractives. The dyeing properties of Hanji were influenced more by dyestuffs extraction method than extraction and dyeing time. Dyeing ability of hot water extractives was superior to cold-water extractives. Without the relation to the time of extraction and dyeing, the color of Hanji dyeing hot water extractives were similar to the control, and the color of Hanji dyed for 45 min with hot water extractives that extracted for 120 min, were almost same as the control. As natural dyestuffs, hot water extractives of rice straw showed that excellent dyeing ability for the development of various natural colors similar to unbleached Hanjis.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.6
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• pp.301-306
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• 2010

The artificial aggregates were fabricated by using the inorganic wastes, dredged soil produced at a dredging work. The input temperature ($800{\sim}1000^{\circ}C$), output temperature ($1100{\sim}1200^{\circ}C$) and heating rate ($5{\sim}10^{\circ}C$/min) in sintering process were controlled to fabricate the aggregates with various value of density and water absorption, and their properties were analyzed as a function of those factors. The specimens sintered at the lower input temperature showed the higher density and the lower water absorption while those with higher input temperature had many pores inside of the aggregates, lower density and higher water absorption. Also increasing the input temperature accelerated the black core phenomenon in the aggregates. The bloating phenomena which the gigantic pores were generated inside the aggregates were improved as increasing the output temperature, but its effect was lower than that of input temperature. It could be realized that the bloating tendency was improved from the results that the density was increased and water absorption was decreased with increasing heating rate from 5 to $10^{\circ}C$/min. It was found that the artificial aggregates of light or heavy weight with various value of density and water absorption could be fabricated by using dredged soils naturally involving gas and fluxing components by controlling the sintering conditions.

• Korean Journal of Remote Sensing
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• v.20 no.5
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• pp.289-305
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• 2004

Atmospheric correction of Landsat Visible and Near Infrared imagery (VIS/NIR) over aquatic environment is more demanding than over land because the signal from the water column is small and it carries immense information about biogeochemical variables in the ocean. This paper introduces two methods, a modified dark-pixel substraction technique (path--extraction) and our spectral shape matching method (SSMM), for the correction of the atmospheric effects in the Landsat VIS/NIR imagery in relation to the retrieval of meaningful information about the ocean color, especially from Case-2 waters (Morel and Prieur, 1977) around Korean peninsula. The results of these methods are compared with the classical atmospheric correction approaches based on the 6S radiative transfer model and standard SeaWiFS atmospheric algorithm. The atmospheric correction scheme using 6S radiative transfer code assumes a standard atmosphere with constant aerosol loading and a uniform, Lambertian surface, while the path-extraction assumes that the total radiance (L/sub TOA/) of a pixel of the black ocean (referred by Antoine and Morel, 1999) in a given image is considered as the path signal, which remains constant over, at least, the sub scene of Landsat VIS/NIR imagery. The assumption of SSMM is nearly similar, but it extracts the path signal from the L/sub TOA/ by matching-up the in-situ data of water-leaving radiance, for typical clear and turbid waters, and extrapolate it to be the spatially homogeneous contribution of the scattered signal after complex interaction of light with atmospheric aerosols and Raleigh particles, and direct reflection of light on the sea surface. The overall shape and magnitude of radiance or reflectance spectra of the atmospherically corrected Landsat VIS/NIR imagery by SSMM appears to have good agreement with the in-situ spectra collected for clear and turbid waters, while path-extraction over turbid waters though often reproduces in-situ spectra, but yields significant errors for clear waters due to the invalid assumption of zero water-leaving radiance for the black ocean pixels. Because of the standard atmosphere with constant aerosols and models adopted in 6S radiative transfer code, a large error is possible between the retrieved and in-situ spectra. The efficiency of spectral shape matching has also been explored, using SeaWiFS imagery for turbid waters and compared with that of the standard SeaWiFS atmospheric correction algorithm, which falls in highly turbid waters, due to the assumption that values of water-leaving radiance in the two NIR bands are negligible to enable retrieval of aerosol reflectance in the correction of ocean color imagery. Validation suggests that accurate the retrieval of water-leaving radiance is not feasible with the invalid assumption of the classical algorithms, but is feasible with SSMM.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.70-74
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• 2011

[ $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ]ceramics was investigated for the application to SOFC ceramic supporter with high porosity and mechanical strength. $ZrO_2$ powder was prepared by combustion method with glycine using the solution of $ZrO(NO_3)_2{\cdot}2H_2O$ dissolved into deionized water and calcination at $800^{\circ}C$ Porous $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ceramics was prepared by sintering the mixture of prepared $ZrO_2$ powder, dolomite and carbon black at $1200{\sim}1400^{\circ}C$ for 1 h. The open porosity ofthe $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ceramics sintered at $1300^{\circ}C$ was over 30 % and increased linearly with the amount of carbon black. The crystal structure of $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ceramics consisted of single cubic phase. The open pore of this ceramics was connected continuously and distributed well on the whole. This ceramics sintered at $1300^{\circ}C$ showed the porosity from 32 to 55 % and mechanical strength from 90 MPa to 30 MPa with increasing the content of added carbon black.