• Korean Journal of Community Nutrition
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• v.8 no.4
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• pp.512-525
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• 2003

The relationship between dietary practices and juvenile delinquency was studied using a dietary survey. Subjects were selected from juvenile delinquents who were under the supervision of the Seoul Probation Office of the Ministry of Justice. The study group consisted of 52 male and 52 female delinquents. As a control group, 104 exemplary high school students were selected in Seoul. A questionnaire was designed to find out the subjects' general characteristics, dietary habits, lifestyle, eating behavior, food frequency, and nutrient intake using the 24-hour recall method. Compared to the exemplary students, the juvenile delinquents were significantly different in education level, family status, monthly allowance, residence status, breast fed, parents' education level, parents' concern. In dietary habits, fifty-eight percent of the juvenile delinquents ate 2 or fewer meals per day, preferred to eat with friends, and liked hot tasting foods. The juvenile delinquents consumed more ion drinks (OR = 9.26 CI: 3.83 -22.37), rameon (OR = 7.67 CI: 3.21 - 18.33), cola (OR = 6.75 CI: 2.91 - 15.69), soft drinks (OR = 6.12 CI: 2.53- 14.81), steamed korean sausage (OR = 5.34 CI:2.31 - 12.32), hamburger (OR = 5.15 CI: 1.91 - 13.87), kimbab (OR = 3.63 CI: 1.76-7.46), ddokbokgi (OR = 3.17 CI: 1.58-6.38), candy (OR = 3.08 CI: 1.41-6.73), white rice (OR = 2.59 CI: 1.19-5.64), hotdog (OR = 2.52 CI: 1.31-4.86), and less rice mixed with grains (OR = 0.02 CI: 0.01-0.05), tangerine (OR = 0.06 CI: 0.02 - 0.20), milk (OR = 0.29 CI: 0.14 - 0.60), roasted fish (OR = 0.32 CI: 0.28-0.99, anchovy (OR = 0.35 CI: 0.17 - 0.72), seaweed (OR = 0.37 CI: 0.16 - 0.83), and tofu (OR = 0.48 CI: 0.23-0.99) than the exemplary students. With respect to the juvenile delinquents, the nutrient intakes lower than 75％ of the Korean RDA were for riboflavin (75.0％) and calcium (47.9％) among the boys, and calcium (46.9％) and iron (60.4％) among the girls. To prevent juvenile delinquency, nutritional education and well-balanced school food service meals should be emphasized so as to improve the management of dietary practices. (Korean J Community Nutrition 8(4) : 512∼525, 2003)

• Journal of Soil and Groundwater Environment
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• v.15 no.3
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• pp.44-51
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• 2010

Contamination of groundwater from point and non-point sources is one of major problems of water resource manangement in Jeju island. This study characterized groundwater and soil contamination in Hallim area which is one of the areas of significantly contaminated soil and groundwater in Jeju Island. The amount of loaded contaminant (ALC) of Jeju area was estimated as 13,212 ton N/yr and 3,210 ton P/yr, The ALC of Hallim area was amounted to 2,895 ton N/yr and 1,102 ton P/yr, which accounted for 21.9% and 34.3% of the Jeju's ALC, respectively. The soil pH values (5.6-5.9) were not much different in land use areas. By contrat, average cation exchange capacity (CEC) of 14.1 $cmol^+/kg$ was high comparing to the nationwide range of 7.7-10.9 $cmol^+/kg$. Further, Sodium adsorption ratios (SARs) of horse ranch, pasture, and cultivating land for livestock were as high as 0.19, 0.17, and 0.16 respectively, comparing to the other landuse areas. Nitrate nitrogen at 22.2% of total groundwater wells exceeded 10 mg/L (the criteria of nitrate nitrogen for drinking water), averaginged 6.62 mg/L with maximum 28.95 mg/L. Groundwater types belonged to Mg-$HCO_3$, Na-$HCO_3$, Ca-$HCO_3$, and Na-Cl, among which Mg-$HCO_3$ type occupied more than 70% of the total samples, indicating the presence of anthropogenic sources. The concentration of nitrate nitrogen was negatively related to altitude and well depth, and positively related to the concentration of Ca, Mg, and $SO_4$ which might originate from chemical fertilizer. The ratio of nitrogen isotopes was estimated as an average of 8.10$^{\circ}/_{\circ\circ}$, and the maximum value of 17.9$^{\circ}/_{\circ\circ}$. According to the nitrogen isotope ratio, the most important nitrogen source was assessed as chemical fertilizer (52.6%) followed by sewage (26.3%) and livestock manures (21.1%).

• Journal of Animal Environmental Science
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• v.17 no.1
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• pp.1-10
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• 2011

This study was conducted to investigate the actual situation of animal medicine use in Hanwoo farms, which were a total of 114 farms. Items surveyed were preference of animal medicine, choice criterion, purchase route, purchase frequency, antibiotics substitution products, etc. Data were collected from May to June, 2010. The kinds of animal medicine which preferred in Hanwoo farms is probiotics (40.4%). Whereas the lowest preference is immunizing agent (12.3%). There was significant difference among regional group (p<0.05), and the significant difference was also found in different farm size group (p<0.05). The factor of choice for purchase of animal medicine was efficiency (31.6%), first of all. There was significant difference among regional group (p<0.05). The purchase route of animal medicine was mostly supplied with the help of government (41.6%). The significant difference were showed in regional group (p<0.05). But that was not found in farm size group (p>0.05). The highest frequency at purchasing antibiotics was less than 1 time per 1 year (38.6%). There was statistically significant difference among regional group (p<0.05). However, there was not significant difference among farm size group (p>0.05). Probiotics of antibiotics substitution products was mostly preferred (50.9%).

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.89-98
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• 2014

Eggs development and early life history of the endangered Korean dwarf loach, Kichulchoia brevifasciata (Teleostei: Cobitidae) was investigated to provide basic information regarding biological characteristics and restoration. Adult fish specimens were sampled using a spoon net at Geurnsan-myeon, Goheung-gun, Jeollanam-do, Korea from June to July 2011. Since, spawning characteristics were analyzed, and females were induced to spawn by injecting Ovaprim (0.5 mL/kg) and their eggs were artificially fertilized with sperms by the dry method in the laboratory. Total length of mature female were 46~76 mm with GSI $9.6{\pm}3.77%$, and total length of mature male was 42~52 mm with GSI $3.5{\pm}1.04%$. Sex ratio (♂/♀) was 0.10, and there were no secondary sexual characteristics. The number of mature eggs was averaged $60{\pm}28.7$ per female. The lemon yellow eggs were slightly adhesive $1.46{\pm}0.07mm$ in diameter. The embryo hatched approximately 66 h after fertilization at $25^{\circ}C$, and the hatched larvae were averaged $5.5{\pm}0.07mm$ in total length (TL). At 6 days after hatching, the larvae averaged $9.0{\pm}0.29mm$(TL) and their yolk sac was completely absorbed. At 17 days after hatching, they entered the juvenile stage and reached $12.6{\pm}0.24mm$ (TL). At 80 days after hatching, the band patterns and external form of the juveniles were similar to those of adults, and they averaged $33.0{\pm}2.19mm$(TL).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.649-658
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• 1995

In order to estimate the level of genetic differences among the pleuronectid species, mitochondrial DNAs were isolated from four species: brown sole, Limanda herensteini; marbled sole, Limanda Yokohamae; stone flounder, Kareius bicoloratus; starry flounder, Platichthys stellatus, and the number of nucleotide substitutions was calculated by the restriction fragment length polymorphisms (RFIPs) generated by f4 sin base recognition restriction endonucleases. Total lengths of the mitochondrial DNA were measured as about 17.6 kbp in all species. Ten different composite genotypes were observed in brown sole, four different genotypes in marbled sole, and two different genotypes in starry flounder. However, only one genotype was observed in stone flounder. The calculated haplotypic diversity value of brown sole was higher than that of marbled sole. The average number of nucleotide substitutions per sites in four species was estimated to be 0.0045 in the intraspecies, 0.0344 in the interspecies, and 0.0457 in the genera, respectively. From these results, we could estimate that the genetic differences among interspecies were not influenced by nucleotide substitutions but genetical discontinuous.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.45-45
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• 2019

This experiment was carried out using artificial clay and LED in the plastic film house (irradiation time: 08:00~18:00/day). Seedlings (n = 63 per $3.3m^2$) of ginseng was planted on May 17, 2018. LED was combined with red and blue light in a 3:1 ratio and irradiated with different light intensity. The average air temperature from April to September was $12.3^{\circ}C$ $-26.0^{\circ}C$ and it was the the highest at $26.0^{\circ}C$ in August. The test area where fluorescent lamp was irradiated tended to be somewhat higher than the LED irradiation area. The chemical properties of the test soil are as follows. pH levels was 5.3~5.5, EC levels 0.45~0.52 dS/m and OM levels 33~37%. The total nitrogen content was 0.35~0.47% and the available $P_2O_5$ contents was 13.7~16.0 mg/kg, which was lower than the suitable level of 70~200 mg/kg. Exchangeable cations K and Mg contents were within acceptable ranges, but the Ca contents was $28{\sim}38cmol^+/kg$ levels higher than the permissible level ($2{\sim}6cmol^+/kg$). Germination of ginseng leaves took 8~9 days and the overall germination rate was 70~75%. The photometric characteristics of LED light intensity are as follows. The greater the light intensity, the higher the PAR (Photosynthetic Action Radiation) value, illuminance and solar irradiation. Photosynthetic rate was also increased with higher light intensity was investigated at $1.7{\sim}3.2{\mu}mol\;CO_2/m^2/s$. Leaf temperature ($23.7{\sim}24.8^{\circ}C$) by light intensity was the same trend. The growth of aerial parts (plant height etc.) were generally excellent when irradiated with 3 times the light intensity, the growth of the ginseng aerial parts were excellent as follows. The plant height was 42.6 cm, stem length was 25.2 cm, leaf length was 9.6 cm and stem diameter was 5.0 mm. The growth of underground part (root length etc.) was the same, and the root length was 24.4 cm, the tap root length was 6.0 cm, diameter of taproot was 18.2 mm and the fresh root weight was 17.2 g. There were no disease incidence such as Alternaria blight, Gray mold and Anthracnose. Disease of Damping off occurred 2.2~3.6% and incidence ratio of rusty root ginseng was 14.6~20.7%. Leaf discoloration rate was 13.7~48.9% and increased with increasing light intensity. Ginsenoside content of ginseng by light intensity is under analysis.

• Journal of Drive and Control
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• v.17 no.4
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• pp.133-140
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• 2020

Traction performance of a tractor varies depending on soil conditions. Sinkage and slip of the driving wheel for tractor frequently occur in a reclaimed land. The objective of this study was to develop a tractor suitable for a reclaimed land. Traction performance was evaluated according to soil conditions of reclaimed land and paddy field. Field experiments were conducted at two test sites (Fields A: paddy field; and Field B: reclaimed land). The tractor load measurement system was composed of an axle rotation speed sensor, a torque meter, a six-component load cell, GPS, and a DAQ (Data Acquisition System). Soil properties including soil texture, water content, cone index, and electrical conductivity (EC) were measured. Referring to previous researches, the tractor traveling speed was set to B3 (7.05 km/h), which was frequently used in ridge plow tillage. Soil moisture contents were 33.2% and 48.6% in fields A and B, respectively. Cone index was 2.1 times higher in field A than in field B. When working in the reclaimed land, slip ratios were about 10.5% and 33.1% for fields A and B, respectively. The engine load was used almost 100% of all tractors under the two field conditions. Traction powers were 31.9 kW and 24.2 kW for fields A and B, respectively. Tractive efficiencies were 83.3% and 54.4% for fields A and B, respectively. As soil moisture increased by 16.4%, the tractive efficiency was lowered by about 28.9%. Traction performance of tractor was significantly different according to soil conditions of fields A and B. Therefore, it is necessary to improve the traction performance of tractor for smooth operations in all soil conditions including a reclaimed land by reflecting data of this study.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.682-692
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• 2013

We investigated out the effect of cultivation region on the physicochemical characteristics of starch in six sweetpotato cultivars. The following sweetpotato cultivars were analyzed: Daeyumi, Shingeonmi, Jinhongmi, Shinyulmi, Yulmi, and Yeonhwangmi. Samples were cultivated in Muan, Iksan, Nonsan, Boryeong and Hamyang. The soil texture was found to be sandy loam in Muan, Iksan, and Boryeong, sandy clay loam in Nonsan, and loam in Hamyang. The starch content of the sweetpotato was higher in Muan than in Hamyang. The amylose content was 22.3-30.9%, and the highest amylose content was found in samples from Iksan. Rapid viscosity analysis showed that the samples from Hamyang had the lowest values of pasting temperature, while samples of the Daeyumi cultivar had the highest values. Thermal analysis with a differential scanning calorimeter showed that the Muan samples had the highest values of onset temperature, maximum peak temperature, and completion temperature, and the samples from Hamyang had the lowest values. There was no difference between the cultivation regions or the cultivar in the X-ray pattern of the starch or its appearance in scanning electron micrographs. Therefore, the results of this study confirm that cultivation region and cultivar play an important role in determining the quality of sweetpotato and the physicochemical characteristics of sweetpotato starch.

• Reproductive and Developmental Biology
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• v.28 no.2
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• pp.83-87
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• 2004

The objective of this study was performed to establish the in vitro culture system of porcine in vitro maturation and in vitro fertilization(IVM/IVF) embryo. These studies was to determine the effects of melatonin, nitric oxide donor(SNP), and the combination effects of SNP and melatonin in porcine IVM/IVF embryos. In routine porcine IVM/IVF procedure, oocytes were cultured for 40∼44h incubation, and the zygotes were cultured for 40∼44h in NCSU 23 medium. Then 2 to 8 cell embryos were removed cumulus cell and were allotted randomly to NCSU 23 containing different concentration of melatonin, SNP and SNP plus melatonin in 5% $O_2$, 5% $CO_2$ and 90% $N_2$ at 38.5$^{\circ}C$. Cell numbers of blastocyst were also counted using double fluorescence stain method. In NCSU 23 medium treated with melatonin 0, 1, 5 and 10 nM, the developmental rate of morula plus blastocysts were 33.3%, 39.1%, 33.3% and 27.9%, respectivly. This result show that the developmental rate of morula and blascytocys treated with 1 nM melatonin was higher than in any other groups(P<0.05). The developmental rates of morula plus blastocysts were 41.9% in 0 uM SNP, 25.6% in 50 uM and 28.4% in 100 uM, respectively. The developmental rate of morula plus blastocysts were decreased treated with SNP in NCSU 23. In combined effects of SNP plus melatonin (0, SNP 50 uM, SNP 50 uM plus melatonin 1 nM, SNP 50 uM plus melatonin 5 nM and SNP 50 uM plus melatonin 10 nM), the developmental rates beyond morula stage of porcine embryos were 31.3%, 34.1%, 39.5%, 29.4% and 39.5%, respectively. The addition of SNP 50 uM plus maltonin 1 nM, developmental rates of blastocyst was higher rate than in any other groups. Cell numbers of blastocyst in NCSU 23 treated with melatonin 0, 1, 5 and 10 nM were 41.0, 42.6, 39.6 and 33.0, respectively. In combined effects of SNP plus melatonin (0, SNP 50 uM, SNP 50 uM plus melatonin 1 nM , SNP 50 uM plus melatonin 5 nM and SNP 50 uM plus melatonin 10 nM), cell numbers of developed blastocyst were 36.3, 34.6, 39.0, 39.9 and 39.0, respectively. These result show that the cell numbers of blastocyst treated with 0, 1 and 5 nM melatonin were higher than in 10 nM group(P<0.05), but cell numbers of blatocyst produced by SNP plus melatonin were not significantly difference in all experimental groups.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.235-243
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• 2007

Macrobenthos were collected in each season by SCUBA diving to investigate the benthic faunal assemblages in the coastal water of Chagwido from September 2004 to August 2005. A total of 201 macrobenthos identified, 74 species (37.2%) of Mollusca were found; 43 species of Arthropoda (19.2%); 34 species of Cnidaria (16.7%) and others including 18 species of Porifera (9.8%). Mean density and biomass were estimated to be 455 individual/$m^2$ and 15,565.0 $g/m^2$, respectively. Whereas annelids was predominant in biomass (1,558.8 g), gastropods were the most dominant faunal group in terms of abundance (5,391 individuals) and the number of species. The dominant species were Trochus sacellus, Batillus cornutus, Pagurus gracilipes, and Cantharus cecillei. The seasonal variation of the number of species and individual Mollusca and Arthropoda was observed. There was a slow increase in spring, the peak in summer, and a slow decrease in autumn and winter. The dominance index was the highest in Gosan and lowest in Yongdang. The biodiversity indice (H') were 1.760-3.497 in each station. Mean biodiversity index was 2.858 (H'). The diversity index, the eveness index (E'), and the dominance index (R) were 3.218-3.743, 0.648-0.720, 17.690-22.826, respectively, in each station.