• Korean Journal of Ichthyology
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• v.12 no.2
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• pp.137-145
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• 2000

The embryonic and larval development of Chelon lauvergnii (Eydoux & Souleyet) was surveyed by incubating artificially inseminated eggs with parent fishes obtained at Kang-wha island in the mid-western coastal area of Korea on June, 1997. The fertilized eggs were transparent, spherical in shape, measuring 0.95~1.08 mm in diameter, having a large oil globule, and their perivitelline space narrow, and began to hatch at 40 hrs. in water temperature $22{\pm}1^{\circ}C$. The newly hatched larvae were 2.35~2.68 mm in total length with 23 myomeres, anus opened, mouth closed, preanal length 58.7~61.6% of total length, oil globule located in posterior end of yolk sac. Melanophores, branch in shape, were distributed mainly along the ventro-lateral region of trunk part and a few on the anterior end of caudal part and surface of oil globule. The larvae measuring 3.08~3.36 mm in total length absorbed yolk material completely in 3 days after hatching, in which air bladder began to appear and mouth opened. In 8 days after hatching, the larva was measured 5.09 mm in total length, its posterior end of notochord began to flex upward and the caudal fin rays differentiated as 7, finfold of the second dorsal and anal fins appeared. In this time, melanophores, branch in shape, were concentrated in the anterior half region of the caudal part and a few also distributed on the top of head, snout region, ventral margin of lower jaw and isthmus region. In 12 days after hatching, the larva measuring 8.48 mm in total length completed all the fins (D. IV-9; P1. 16; P2. I, 5; A. II, 9) and reached to the juvenile stage. Melanophores, in this time, were distributed on the mid-lateral region of the caudal part in enlargment than before and a few also found in the dorso-lateral region of the trunk part, and in the cheek region.

• Journal of the Korean earth science society
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• v.38 no.1
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• pp.24-34
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• 2017

The westerly waves generation is described in the advanced earth science textbook used at high school as follows: as westerly wind approaches and blows over large mountains, the air flow shows wave motions in downwind side, which can be explained by the conservation of potential vorticity. However, there has been no case study showing the phenomena of the mesoscale westerly waves with observational data in the area of small mountains in Korea. And thus the wind speed and time persistency of westerly winds along with the width and length of mountains have never been studied to explain the generation of the westerly waves. As a first step, we assured the westerly waves generated in the downwind side of Sobaek mountains based on surface station wind data nearby. Furthermore, the critical or minimum wind velocity of the westerly wind over Sobaek mountains to generate the downwind wave were derived and calcuated tobe about $0.6m\;s^{-1}$ for Sobaek mountains, which means that the westerly waves could be generated in most cases of westerly blowing over the mountains. Using surface station data and 4-dimensional assimilation data of RDAPS (Regional Data Assimilation and Prediction System) provided by Korea Meteorological Agency, we also analyzed cases of westerly waves occurrence and life cycle in the downwind side of Sobaek mountains for a year of 2014. The westerly waves occurred in meso-${\beta}$ or -${\gamma}$ scales. The westerly waves generated by the mountains disappeared gradually with wind speed decreasing. The occurrence frequency of the vorticity with meso-${\beta}$ scale got to be higher when the stronger westerly wind blew. When we extended the spatial range of the analysis, phenomena of westerly waves were also observed in the downwind side of Yensan mountains in Northeastern China. Our current work will be a study material to help students understand the atmospheric phenomena perturbed by mountains.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.363-373
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• 2007

To evaluate environment of farm lands using indicator insects and evaluation indices, the insect abundance of which is one of the major criteria for the evaluation of agricultural environment of farm land in urban areas and industrial complex, three sites (Ansan, Daesan, Suncheon) were designated and monitored from 2004 to 2006. The flora of agricultural land was more than urban areas and industrial complex of that in three sites. Soil, water and air pollution of urban areas and industrial complex were more serious than those of agricultural land in three sites. Overall population of insects were high from June to August in the surveyed three sites. Collected insects in agricultural land were 12 order, 106 family and 166 species, those in urban areas were 11 order, 102 family and 148 species, and in industrial complex were 11 order, 100 family and 152 species. Species and population belonging to Coleoptera was dominant in the surveyed sites. The insect diversity indices of farm land were 2.36 in agricultural land, 1.92 urban areas and industrial complex. And agricultural environment of agricultural land was good, urban areas was common and industrial complex was poor. Based on the major criteria of evaluation items, the criteria were selected as diversity index over 2.1, insect indicator Pheropsophus javanus in agricultural land, diversity index 1.5-2.0, insect indicator Nephotettix cincticeps in urban areas, diversity index below 1.5, insect indicator Pagria signata in industrial complex.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.93-99
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• 2015

The purpose of this study was to determine the appropriate temperature for water curtain in greenhouses equipped with recirculated water curtain system. The study analyzed the changes in air temperature in non-heated greenhouses for strawberry cultivation based on outdoor temperature, water curtain temperature and night time. Three greenhouse units were used for this study: The first unit was assigned as a control (no water curtain system), two other greenhouses were equipped with recirculated water curtain system with water curtain temperatures of $10^{\circ}C$ and $15^{\circ}C$, respectively. Analysis showed that the indoor temperatures were directly correlated with the outdoor temperature in all experimental greenhouses. Heat insulating effect of $15^{\circ}C$ water curtain was increased by $1.3^{\circ}C$ compared to that in $10^{\circ}C$ water curtain system. The $15^{\circ}C$ water curtain treatment showed the highest average temperature and less temperature variation in comparison with control and $10^{\circ}C$ water curtain treatment. To maintain indoor temperature at $5^{\circ}C$, water curtain temperature of $10^{\circ}C$ was suitable when outdoor minimum and average temperatures were -1.3 and $1.5^{\circ}C$, and water curtain temperature of $15^{\circ}C$ was suitable when outdoor minimum and average temperatures were -4.7 and $-0.2^{\circ}C$, respectively. The highest temperature in greenhouses according to measurements in different periods of night time was observed after sunset (18:30-20:30), and the lowest temperature before sunrise (05:00-07:00). Water curtain maintained a target indoor temperature by acting as a layer of heat transfer insulator which decreased heat loss from greenhouses. Therefore, water temperature in recirculating water curtain systems should be determined by considering outdoor temperatures, changes in temperature at different periods of night time, and cultivated crop.

• Korean Journal of Ichthyology
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• v.6 no.2
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• pp.132-159
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• 1994

The taxonomic revision of the family Congridae was made based on the specimens collected from the south-western coasts of the Korea from June 1988 to Oct. 1993. The family Congridae was classified into 8 species belonging to 6 genera. based on the external and internal morphological characters : Anago anago, Ariosoma anagodies, Ariosoma shiroanago shiroanago, Conger myriaster, Conger japonicus, Gnathophis nystromi nystromi, Rhechias retrotincta and Uroconger lepturus. Among the species reported as the congrid eels from Korea until now, four species were transferred into different generic or specific name Conger flavirostris into Ariosoma anagoides ; Astroconger myriaster into Conger myriaster ; Congrina retrotincta into Rhechias retrotincta and Rhynchocymba nystromi into Gnathophis nystromi nystromi. A Korean congrid eel, Ariosoma shiroanago shiroanago, was reported for first time in Korea. Intergeneric characters of the family Congridae were the form of the lateralline scales, the state of the tip of tail, the segmented state of the dorsal and anal fin rays, the existance of the supraoccipital bone and of lateral ethmoid process of the skull, the origin of dorsal fin and the forms of upper labial flange. The interspecific classification was made according to the characters such as the numbers of sensory pores of head part and in front of vent, teeth rows and numbers of upper and lower jaw, the numbers of vertebrae, the body color, the shapes of the head part, the color of intestine, the size of eye, the structure of air bladder and the number of branchiostegal rays. A new key on the taxonomical characteristics to the genera and species of the family Congridae has been estabilished and their distribution in Korea is described.

• Food Science and Preservation
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• v.24 no.6
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• pp.746-757
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• 2017

This study was performed to evaluate the effect of different freezing conditions and storage periods on physicochemical and microbial characteristics of garlic. Garlics were washed, dried, sliced to 0.3 cm then packed in LDPE+LLDPE film bags. They were treated with still-air freezing at $-20^{\circ}C$ (SAF20), $-40^{\circ}C$ (SAF40) and immersed-liquid freezing at $-40^{\circ}C$ (ILF40). Frozen garlics were stored under frozen storage conditions for 7 months at $-20^{\circ}C$ and quality characteristics were measured monthly during the frozen storage. Freezing rate of garlic was the fastest in ILF 40 (10 min), SAF40 (40 min) and SAF20 (1,600 min) sequentially. In ILF40, drip loss, cutting force, total aerobic bacteria count and pH were the lowest, whereas pyruvic acid and allicin content were the highest (p<0.05) during frozen storage, these results were the most similar characteristics with the fresh garlic. During frozen storage, drip loss, color difference and total organic acid content were significantly fluctuated in SAF20 (p<0.05), while they were not changed in ILF40. Overall, total aerobic bacteria count and pH decreased, cutting force, pyruvic acid and allicin content remained unchanged in all groups. In conclusion, the optimal freezing conditions for garlic with the least quality changes was considered to be ILF40 (immersed liquid freezing), keeping quality characteristics up to 7 months by freezing storage.

• Journal of Korean Society of Forest Science
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• v.103 no.1
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• pp.37-42
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• 2014

Fine root distribution was investigated in Pinus densiflora stands using soil core sampling and minirhizotrons, and conversion factors and regression equations were developed for converting minirhizotron data into fine root biomass. Fine root biomass was measured by soil core sampling from October, 2012 to September, 2013 once a month except for the winter, and surface area of fine roots was estimated by minirhizotrons from May to August, 2013 once a month. Fine root biomass and surface area were significantly higher in the upper soil layers than in the lower soil layers. Fine root biomass showed seasonal patterns; the mean fine root biomass ($kg{\cdot}ha^{-1}$) in summer (3,762.4) and spring (3,398.0) was significantly higher than that in autumn (2,551.6). Vertical and seasonal patterns of fine root biomass might be related to the soil bulk density, nutrient content and temperature with soil depth, and seasonal changes of soil and air temperature. Conversion factors (CF) between fine root surface area from minirhizotron data and fine root biomass from soil core sampling were developed for the three soil depths. Then a linear regression equation was developed between the predicted fine root biomass using CF and the measured fine root biomass (y = 79.7 + 0.93x, $R^2=0.81$). We expect to estimate the long-term dynamics of fine roots using CF and regression equation for P. densiflora forests in Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.7
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• pp.881-897
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• 2019

We reconstructed and digitized the National Institute of Fisheries Science (NIFS) Serial Oceanographic observations (NSO) and Coastal Oceanographic observations (NCO) data attained prior to 1961 through historical oceanographic observation data rescue projects. Increasing trends of long-term sea surface temperature (SST) were shown from the NSO data of 21 available stations for the past 80 to 92 years. In general agreement with previous research results used in the data of the past 50 years, we calculated the rate of temperature rise. As a result of analyzing the spatial distribution of SST change rate in the Korean of shore region using selected oceanographic data, the West Sea and South Sea showed a higher tendency of temperature rise in the offshore area than in the coastal area. However, unlike the results of previous studies, the East Sea (Gangwon Line and Ulsan Line) showed a lower water temperature rise than the coastal stations. Annual fluctuations of NCO's SST data from 1989 to 1998 for three stations representing the East Sea, South Sea, and West Sea, (Jumunjin, Geomundo and Budo, respectively) revealed that the East Sea showed the highest SST increase for the 10 years. The increases were 1.63 ℃ at Jumunjin, 1.16 ℃ at Geomundo, and 0.79 ℃ at Budo. As a result of the investigation, it can be concluded that SST is repeatedly rising and falling with a period of 3 ~ 6 years. Especially, since the 1980s, most of the stations show positive anomalies of SST. Lastly, to understand ocean_atmosphere interactions, we analyzed the correlations between SST of the NCO stations and air temperature around them and the results were 0.76 for the South Sea (Geomundo), 0.34 for the West Sea (Budo), and 0.32 for the East Sea (Jumunjin) with the highest correlation in the South Sea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1388-1394
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• 2012

The physiological functionalities of 70% ethanol extracts (EE) from Cudrania tricuspidata fruit (ECFD, EE of C. tricuspidata subjected to freeze-drying; ECHD, EE of C. tricuspidata subjected to heat air drying; ECID, EE of C. tricuspidata subjected to infrared drying) were investigated. Yields of freeze-dried powders of ECFD, ECHD, and ECID were 51.50%, 53.91%, and 56.14%, respectively. Color $L^*$, $a^*$, $b^*$, and $H^{\circ}$ values of ECHD and ECID decreased. Dried ECHD and ECID had relatively higher contents of total polyphenolics and flavonoids than ECFD. Electron donating abilities at a concentration of 10 mg/mL (w/v) were in order of ECID (62.37%) >ECHD (80.17%)>ECFD (77.80%). Reducing powers ($OD_{700}$) of ECFD, ECHD, and ECID were 0.75, 1.70, and 1.89, respectively. Additionally, ABTS radical scavenging ability of ECID was the highest with a value of 62.37% at a concentration of 10 mg/mL (w/v). Nitrite scavenging activities of ECFD, ECHD, and ECID at a concentration of 10 mg/mL (w/v) were 28.76%, 30.69%, and 41.64%, respectively. SOD (superoxide dismutase)-like activities at 5 mg/mL (w/v) were in the order ECFD (891.93 mUnits)>ECHD (723.02 mUnits)>EFID (611.97 mUnits). Whereas ferrous ion chelating activity of ECFD (52.36%) and ECID (47.16%) was significantly higher than that of ECHD (30.04%). ACE inhibitory and xanthine oxidase (XO) inhibitory activities of ECHD and ECID at a concentration of 1 mg/mL (w/v) were higher than those of ECFD. In conclusion, we provided experimental evidence that extracts of pre-dried C. tricuspidata exhibit increased physiological functionalities. Further, infrared drying technique is the best method for enhancement of antioxidant activity of C. tricuspidata fruit.

• Journal of Sensor Science and Technology
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• v.6 no.4
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• pp.328-336
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• 1997

The CdSe thin films were grown on the Si(100) wafers by a hot wall epitaxy method (HWE). The source and substrate temperature are $600^{\circ}C$ and $430^{\circ}C$ respectively. The crystalline structure of epilayers was investigated by double crystal X-ray diffraction(DCXD). Hall effect on the sample was measured by the van der Pauw method and studied on the carrier density and mobility dependence on temperature. From Hall data, the mobility was increased in the temperature range 30K to 150K by impurity scattering and decreased in the temperature range 150k to 293k by the lattice scattering. In order to explore the applicability as a photoconductive cell, we measured the sensitivity(${\gamma}$), the ratio of photocurrent to darkcurrent(pc/dc), maximum allowable power dissipation(MAPD), spectral response and response time. The results indicated that the photoconductive characteristic were the best for the samples annealed in Cu vapor compare with in Cd, Se, air and vacuum vapour. Then we obtained the sensitivity of 0.99, the value of pc/dc of $1.39{\times}10^{7}$, the MAPD of 335mW, and the rise and decay time of 10ms and 9.5ms, respectively.