• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.172-180
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• 2009

This study was carried out to compare the physicochemical characteristics and sensory quality of Sogokju (Korean traditional rice wine) prepared with waxy rice varieties. Among tested waxy rice varieties, highest protein contents (8.11%) was observed in cv. Sangjuchal, and highest whiteness and L-value were observed in cv. Hwaseonchal, while no significant differences in gelatinization temperature could be observed among tested varieties, and cv. Boseokchal and Sinseonchal exhibited higher breakdown viscosity compared to the others. The alcohol contents of Sogokju with waxy rice varieties ranges from 13.0 to 13.4%, and the brix degree and turbidity were within the range of 20.5 to 24.6 $^{\circ}Bx$, and 0.0344 to 0.0530, respectively. The highest L-value (6.90), b-value (l.45), pH (4.79), total acidity (0.8384%), and glucose content (10.843 g/100 ml) could be observed in Sogokju made with cv. Sangjuchal. The organic acids such as succinic acid, malic acid, citric acid and oxalic acid could be detected in Sogokju. Although no variety-dependant differences in appearance, aroma, and taste could be found in sensory evaluation, Sogokju made with cvs. Sinseonchal, Haepyeongchal, and Hwaseonchal showed higher overall quality than Sogokju made with cv. Dongjinchal, which is most widely used for Sogokju used for Sogokju production nowadays.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.10 no.1
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• pp.1-18
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• 1974

Some coastal oceanographic investigations in Kwang Yang Bay were carried out bimonthly from April to September (The first half period of the research project) in 1974. The behaviour of the waters, distributions of water temperature and salinity and diffusion characteristic by dye release experiments in the bay are studied for the problems of practical importance in connection with water pollution. Velocities and directions of tidal currents at five fixed stations were observed. And dye diffusion experiment was also carried out on the sea. According to the results from this study, the salinity of the water is lower, ranging from about $28\;\textperthousand\;to\;32\textperthousand$, on all over the surface in the bay with the cause that the fresh water flows in from the Sumjin river. Diffusivities in this sea by means of Rhodamine B diffusion elliperiment were $785.6\;{\times}\;10^2\;\textrm{m}^2/sec$ in major axis, $15.6\;{\times}\;10^2 \;\textrm{m}^2/sec$/sec in minor axis in the direction on patch after 30 minutes from the dye release.

• International Journal of Ocean System Engineering
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• v.2 no.3
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• pp.185-194
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• 2012

A Macroscopic combination of two or more distinct materials is commonly referred to as a "Composite Material", having been designed mechanically and chemically superior in function and characteristic than its individual constituent materials. Composite materials are used not only for aerospace and military, but also heavily used in boat/ship building and general composite industries which we are seeing increasingly more. Regardless of the various applications for composite materials, the industry is still limited and requires better fabrication technology and methodology in order to expand and grow. An example of this is that the majority of fabrication facilities nearby still use an antiquated wet lay-up process where fabrication still requires manual hand labor in a 3D environment impeding productivity of composite product design advancement. As an expert in the advanced composites field, I have developed fabrication skills with the use of machinery based on my past composite experience. In autumn 2011, the Korea government confirmed to fund my project. It is the development of a composite sanding machine. I began development of this semi-robotic prototype beginning in 2009. It has possibilities of replacing or augmenting the exhaustive and difficult jobs performed by human hands, such as sanding, grinding, blasting, and polishing in most often, very awkward conditions, and is also will boost productivity, improve surface quality, cut abrasive costs, eliminate vibration injuries, and protect workers from exposure to dust and airborne contamination. Ease of control and operation of the equipment in or outside of the sanding room is a key benefit to end-users. It will prove to be much more economical than normal robotics and minimize errors that commonly occur in factories. The key components and their technologies are a 360 degree rotational shoulder and a wrist that is controlled under PLC controller and joystick manual mode. Development on both of the key modules is complete and are now operational. The Korean government fund boosted my development and I expect to complete full scale development no later than 3rd quarter 2012. Even with the advantages of composite materials, there is still the need to repair or to maintain composite products with a higher level of technology. I have learned many composite repair skills on composite airframe since many composite fabrication skills including repair, requires training for non aerospace applications. The wind energy market is now requiring much larger blades in order to generate more electrical energy for wind farms. One single blade is commonly 50 meters or longer now. When a wind blade becomes damaged from external forces, on-site repair is required on the columns even under strong wind and freezing temperature conditions. In order to correctly obtain polymerization, the repair must be performed on the damaged area within a very limited time. The use of pre-impregnated glass fabric and heating silicone pad and a hot bonder acting precise heating control are surely required.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.237-248
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• 2018

The vertical distribution of hydrometeor before precipitation near the cloud base has been analyzed using a scanning lidar, rawinsonde data, and Cloud-Resolving Storm Simulator (CReSS). This study mostly focuses on 13 Desember 2016 only. The typical synoptic pattern of lake-effect snowstorm induced easterly in the Yeongdong region. Clouds generated due to high temperature difference between 850 hPa and sea surface (SST) penentrated in the Yeongdong region along with northerly and northeasterly, which eventually resulted precipitation. The cloud base height before the precipitation changed from 750 m to 1,280 m, which was in agreement with that from ceilometer at Sokcho. However, ceilometer tended to detect the cloud base 50 m ~ 100 m below strong signal of lidar backscattering coefficient. As a result, the depolarization ratio increased vertically while the backscattering coefficient decreased about 1,010 m~1,200 m above the ground. Lidar signal might be interpreted to be attenuated with the penetration depth of the cloud layer with of nonspherical hydrometeor (snow, ice cloud). An increase in backscattering signal and a decrease in depolarization ratio occured in the layer of 800 to 1,010 m, probably being associated with an increase in non-spherical particles. There seemed to be a shallow liquid layer with a low depolarization ratio (<0.1) in the layer of 850~900 m. As the altitude increases in the 680 m~850 m, the backscattering coefficient and depolarization ratio increase at the same time. In this range of height, the maximum value (0.6) is displayed. Such a result can be inferred that the nonspherical hydrometeor are distributed by a low density. At this time, the depolarization ratio and the backscattering coefficient did not increase under observed melting layer of 680 m. The lidar has a disadvantage that it is difficult for its beam to penetrate deep into clouds due to attenuation problem. However it is promising to distinguish hydrometeor morphology by utilizing the depolarization ratio and the backscattering coefficient, since its vertical high resolution (2.5 m) enable us to analyze detailed cloud microphysics. It would contribute to understanding cloud microphysics of cold clouds and snowfall when remote sensings including lidar, radar, and in-situ measurements could be timely utilized altogether.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.657-663
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• 2012

To evaluate effects of water temperatures on nutrient releases of submerged plants in lake reservoir, COD, T-N and T-P releases of submerged plants were investigated for 60 days under different incubation temperatures ($5^{\circ}C$ and $25^{\circ}C$) in columns. The amounts of COD releases by Carex dimorpholepis were $60.4mg\;L^{-1}$ at $5^{\circ}C$ and $78.0mg\;L^{-1}$ at $25^{\circ}C$. In Miscanthus sacchariflorus, the amounts of COD releases were $62.5mg\;L^{-1}$ at $5^{\circ}C$ and $70.5mg\;L^{-1}$ at $25^{\circ}C$. The amounts of T-N releases in Carex dimorpholepis at $5^{\circ}C$ and $25^{\circ}C$ were 45.8 and $60mg\;L^{-1}$, respectively. In Miscanthus sacchariflorus, the amounts of T-N releases were $55.7mg\;L^{-1}$ at $5^{\circ}C$ and $61.0mg\;L^{-1}$ at $25^{\circ}C$. At $5^{\circ}C$, the amounts of T-P releases in Carex dimorpholepis and Miscanthus sacchariflorus were 5.65 and $7.10mg\;L^{-1}$, respectively. At $25^{\circ}C$, the amounts of T-P releases in Carex dimorpholepis and Miscanthus sacchariflorus were 8.70 and $8.18mg\;L^{-1}$, respectively. In the column experiment, the amounts of COD, T-N and T-P releases by submerged plants at $25^{\circ}C$ were generally higher than those at $5^{\circ}C$.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.23-30
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• 2007

The ultimate objective of this study is to develop oxygen-enriched combustion techniques applicable to the system of practical industrial boiler. To this end the combustion characteristics of lab-scale LNG combustor were investigated as a first step using the method of numerical simulation by analyzing the flame characteristics and pollutant emission behaviour as a function of oxygen enrichment level. Several useful conclusions could be drawn based on this study. First of all, the increase of oxygen enrichment level instead of air caused long and thin flame called laminar flame feature. This was in good agreement with experimental results appeared in open literature and explained by the effect of the decrease of turbulent mixing due to the decrease of absolute amount of oxidizer flow rate by the absence of the nitrogen species. Further, as expected, oxygen enrichment increased the flame temperatures to a significant level together with concentrations of $CO_2$ and $H_2O$ species because of the elimination of the heat sink and dilution effects by the presence of $N_2$ inert gas. However, the increased flame temperature with $O_2$ enriched air showed the high possibility of the generation of thermal $NO_x$ if nitrogen species were present. In order to remedy the problem caused by the oxygen-enriched combustion, the appropriate amount of recirculation $CO_2$ gas was desirable to enhance the turbulent mixing and thereby flame stability and further optimum determination of operational conditions were necessary. For example, the adjustment of burner with swirl angle of $30\sim45^{\circ}$ increased the combustion efficiency of LNG fuel and simultaneously dropped the $NO_x$ formation.

• Magazine of the Korean Society of Agricultural Engineers
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• v.14 no.2
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• pp.2622-2633
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• 1972

This study was attempted in order to search for phyosical properties on various mix designs of concrete as ne of studies relating top revention against corrosion by action of sea water in the West Sea. In this study, as concerete mix design, fly ash, pozzolith and vinsolresin were used as admixtures for normal portland cement respectively, and pozzolan cement and normal cement were also used for each plain concrete. Concrete specimens were made and cured in accordance with the Korean Standard Specifications for concrete. In thetest, compressive strengths of the specimens were measured at the following ages; 7-day, 28-days and 3-months. Absorption test was made by immersing the specimens in water kept at boiling temperature for 5 hours. The results obtained from the tests are summarized as follows; 1. The use of fly ash as an admixture in mix design of concrete, has an effect on compressive strength at each age. But it is actually not effective on absorption by concrete, as the result of the fly ash concrete is almost the same at that of ordinary plain concrete. 2. The use of pozzolith as an admixture in mix design of concrete, has an effect on both of compressive strength at each age and absorption rate. The pozzolith is more effective than vinsol resin, relating to improvement for physical proreties of concrete. 3. The use of vinsol resin as an admixture in mix design of concrete, has also an effect on both of compressive strength at each age and absorption rate. As the above fact, effectiveness of the vinsol resin is some what lower than pozzolith, as far as physical properties of the concrete are concerned. 4. Plain concrete used pozzolan cement only is the most effective on both of strength at each age and absorption rate in this study. The pozzolan cement is characteristic of higher strenth as the age is later. 5. Relationship between compreessive strengths and absorption rates of the concrete is shown by a different regression line dependingon ages. The gradient of the regression line is steeper as the age is later. 6. Throught physical test, it may be expected that the use of pozzolith and vinsol resinas asan admixture respectively will be better resistant than fly ash or ordinary plain concrete and that plain pozzolan concrete will also be the best resistant to action of sea water due to improvement of theirphysical properties.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.24 no.6
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• pp.229-236
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• 2014

A stoichiometric mixture of evaporating materials for $MnAl_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $MnAl_2S_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperatures were $630^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The temperature dependence of the energy band gap of the $MnAl_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.7920eV-5.2729{\times}10^{-4}eV/K)T^2/(T+786 K)$. In order to explore the applicability as a photoconductive cell, we measured the sensitivity (${\gamma}$), the ratio of photocurrent to dark current (pc/dc), maximum allowable power dissipation (MAPD) and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in S vapour compare with in Mn, Al, air and vacuum vapour. Then we obtained the sensitivity of 0.93, the value of pc/dc of $1.10{\times}10^7$, the MAPD of 316 mW, and the rise and decay time of 14.8 ms and 12.1 ms, respectively.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.197-213
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• 2012

This study was performed to know the community structure of macrobenthos and environmental factors at each 16 stations in the subtidal sandy bottoms of the southern coastal water of Jeju Island from July to November, 2011. Mean temperature and mean salinity were $20.2-22.7^{\circ}C$, 33.7-34.9 psu which shows stable water messes. Chlorophyll a concentrations of phytoplankton ranged from 0.71 to 1.71 mg/L (1.11 mg/L), showing higher July than September and November with a blooming in summer. The mean concentration values (the ranges in parentheses) of nitrate, phosphate, and silicate are 0.029-0.206 mg/L (0.101 mg/L), 0.001-0.027 mg/L (0.007 mg/L), 0.024-0.682 mg/L (0.454 mg/L), respectively. However, the values higher coastal zone due to influxes from the land. A total of 37 species was identified. of these mollusca comprised 29 secies (78.4%); Echinodermata 5 (13.5%); Arthropoda 3 (8.1%). density and biomass were estimated to be 550 ind./$m^2$ and 20,951.8 gwwt/$m^2$, respectively. Mollusca were the most dominant faunal group in terms of abundance (481 ind./$m^2$) and number of species as well, whereas bivalves were predominant in biomass (16,647.6 gwwt/$m^2$). The dominant species were Vasticardium burchardi, Oblimopa japonica, Mactar achatina, Bornatemishistrioiw akawai, Paphia vernicosa, Amusium japonicum, Glycymeris albolineata, Astriclypeus manni in 15-30 m. The seasonal variation appeared as distinct, Mollusca of individual and biomass. When summer was make a slow increase, after the highest decrease in autumn. The abundance of macrobenthic invertebrates showed significant correlation with environmental factors (Chlorophyll a, DIN, $SiO_2$, Fine sand, Very fine sand) in almost all sampling depths. The biodiversity, evenness richness index were appeared 1.56-2.50 (H'), 0.49-0.80 (E'), 4.12-4.67 (R) in each stations. The dominace index were appeared Highest in November and lowest in September.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.37-42
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• 2002

This study was performed to provide basic that will predict the usefulness of Gastrodiae Rhizoma as food materials. The physicochemical properties of raw, freeze-dried, and hot air-dried Gastrodiae Rhizoma were investigated and analyzed. The moisture content of raw Gaxtrodiae Rhizoma was 81.20%. The moisture, crude protein, crude fat, crude ash and carbohydrates of freeze-dried Gastrodiae Rhizoma were 7.61%, 6.21%, 1.50%, 2.55%, and 89.74%, respectively. The total dietary fiber (TDF) of freeze-dried Gastrodiae Rhizoma was 11.68%. The K (1265.03 mg%) was the highest mineral found in Gastrodiae Rhizoma. Aspartic acid (1272.10 mg%) and glutamic acid (1249.50 mg%) in Gastrodiae Rhizoma were major amino acids. Linoleic acid (53.79%), palmitic acid (20.17%), oleic acid (11.93%), and linolenic acid (4.78%) were principal fatty acids in crude fat of Gaxtrodiae Rhizoma. Most of the free sugars of freeze-dried Gastrodiae Rhizoma was maltose (11.04%). In color, the freeze-dried showed the highest lightness (94.52) and the $60^{\circ}C$ hot air-dried showed the highest redness(0.76) and yellowness (16.41). The color differences among freeze-dried, $40^{\circ}C$ hot air-dried, and $60^{\circ}C$ hot air-dried Gastrodiae Rhizoma were distinguished markedly. Vitamin C contents in raw, freeze-dried, and $60^{\circ}C$ hot air-dried Gastrodiae Rhizoma were 0.015%, 0.010%, and 0.002%, respectively. The organoleptic characteristics of raw, freeze-dried, and hot air-dried Gastrodiae Rhizoma were evaluated and compared on the basis, 5 points of raw Gastrodiae Rhizoma by 9 points scale. The undesirable characteristics, such as fishy odor, sewage odor, bitter taste, bad and salty taste, decreased, while desirable characteristic such as sweet taste was maintained or increased considerably as drying temperature got higher.