• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.699-708
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• 2017

The present study was to develop an approach for predicting soybean yield using a crop growth simulation model at the regional level where the detailed and site-specific information on cultivation management practices is not easily accessible for model input. CROPGRO-Soybean model included in Decision Support System for Agrotechnology Transfer (DSSAT) was employed for this study, and Illinois which is a major soybean production region of USA was selected as a study region. As a first step to predict soybean yield of Illinois using CROPGRO-Soybean model, genetic coefficients representative for each soybean maturity group (MG I~VI) were estimated through sowing date experiments using domestic and foreign cultivars with diverse maturity in Seoul National University Farm ($37.27^{\circ}N$, $126.99^{\circ}E$) for two years. The model using the representative genetic coefficients simulated the developmental stages of cultivars within each maturity group fairly well. Soybean yields for the grids of $10km{\times}10km$ in Illinois state were simulated from 2,000 to 2,011 with weather data under 18 simulation conditions including the combinations of three maturity groups, three seeding dates and two irrigation regimes. Planting dates and maturity groups were assigned differently to the three sub-regions divided longitudinally. The yearly state yields that were estimated by averaging all the grid yields simulated under non-irrigated and fully-Irrigated conditions showed a big difference from the statistical yields and did not explain the annual trend of yield increase due to the improved cultivation technologies. Using the grain yield data of 9 agricultural districts in Illinois observed and estimated from the simulated grid yield under 18 simulation conditions, a multiple regression model was constructed to estimate soybean yield at agricultural district level. In this model a year variable was also added to reflect the yearly yield trend. This model explained the yearly and district yield variation fairly well with a determination coefficients of $R^2=0.61$ (n = 108). Yearly state yields which were calculated by weighting the model-estimated yearly average agricultural district yield by the cultivation area of each agricultural district showed very close correspondence ($R^2=0.80$) to the yearly statistical state yields. Furthermore, the model predicted state yield fairly well in 2012 in which data were not used for the model construction and severe yield reduction was recorded due to drought.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.147-158
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• 2008

In this study, fermentation characteristics of waste agricultural and forest biomass for production of heat energy were focused to be used in agricultural farm households. The purpose of this study was focused on seeking practical utilization of agricultural and forest biomass wastes in agricultural farm households in the form of thermal energy by means of simple fermentation process. Fermentation process was performed in terms of different raw-materials and their mixture with different ratios. Urea, lime, and bioaids were added as fermenting aids. Moisture contents of fermenting substrates were adjusted to 55~65%. In order to optimize the fermentation process various factors, such as raw-materials, moisture contents, amount of fermenting aids, and practical measurement of hot-water temperature during fermentation were carefully investigated. The optimum condition of fermenting process were obtained from hardwood only and hardwood: softwood (50 : 50) beds. In case of hardwood only the highest temperature was recorded between 60 to $90^{\circ}C$ the lowest temperature was determined to more or less $40^{\circ}C$ and the average temperature was ranged to $50{\sim}60^{\circ}C$ and this temperature ranges were maintained up to 20~30 days. The optimum amount of additives were estimated to ca. 15 kg of urea, 20 kg of bioaids, and 10 kg of lime for 1 ton of substrate. To reach the highest temperature the optimum moisture content of fermenting substrate was proved to 55% among three moisture content treatments of 45%, 55% and 65%. The temperature of hot-water tank installed in fermenting bed of hardwood : grass (50 : 50) showed very different patterns according to measuring positions. In general, temperatures in the mid- and upper-parts of substrate piling were relative higher than lower and surface parts during 45-day fermentation process. The maximum temperature of fermenting stage was determined to $65^{\circ}C$, minimum temperature, more or less $40^{\circ}C$, and average temperature was $60^{\circ}C$. The water temperature of tank exit was ranged to $33{\sim}48^{\circ}C$ during whole measuring periods. It could be concluded that fermentation process of waste agricultural and forest biomass produces a considerable amounts of heat, averaging about $50{\sim}60^{\circ}C$ for maximum 3 months by using the heat exchanger (HX-helical type).

• Journal of Aquaculture
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• v.8 no.4
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• pp.261-269
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• 1995

A practical control diet was prepared and compared with raw fish ($80\%$ frozen horse mackerel + $20\%$ commercial binder meal) and moist pellet ($50\%$ frozen horse mackerel + $50\%$commercial binder meal) diets to develop a practical diet formulation for Korean rockfish (Sebastes schlegeli). Korean rockfish averaging 68.5g were fed with the three experimental diets for 11 months. Final average body weight was approximately 330g and showed no significant difference between fish groups (P>0.05). Feed efficiency of fish from control diet was significantly lower than those of fish from raw fish and moist pellet diets (P<0.05). Protein and lipid retention efficiency of fish ranged $26.9-28.8\%$ and $86.5-110.2\%$, respectively, without any significant difference between the different diets. At the end of the experiment, chemical composition for the various parts of fish body and flesh quality of the raw fish were examined. The data showed that there was no significant difference between fish from the different diet groups for moisture, protein and lipid contents of whole body, liver, and dorsal muscle. Also, thirty three panelists did not find any difference in color, smell, texture, and taste of the raw fish flesh. These results suggest that Korean rockfish can be cultured with a laboratory practical feed without any negative effects on growth, nutrient utilization, chemical composition of fish, and quality of raw fish. Therefore, the next step in developing practical feed is to modify the control diet for improving fish performance and reducing feed cost.

• Korean Journal of Occupational Health Nursing
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• v.7 no.2
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• pp.164-176
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• 1998

This study deals with the current medical utilization for migrant workers and the characteristics of them. The purpose of this study is to provide the basic information to establish proper medical policy. For the study self-made questionnaire was used, which was answered by 453 migrant workers working in the area of manufacturing and non-technical work in 10 cities like Seoul, Inchon, Namyangju, Sungnam, Kwangju, Pyungchon, Kunpo, Kimpo, Masuk in Kyungki-do and Chunan in Chungchungnam-do. Besides, 303 medical records of those who had visited free medical check-up center were analyzed. The period of accumulating data is 6 months, from November 1st, 1996 to April 30th, 1997. The characteristics of migrant workers and current medical utilization are analyzed by percentage and the relation between characteristics and current medical utilization were analyzed using ${\chi}^2$-test, t-test, ANOVA. The finding of this study was as follows : 1) The number of nationality was 16. The first majority was Philippians as 32.0%. Among 16 nationalities Southeastern and Northern Asians were 48.9%, Southwestern Asian was 46.5%, the rest was 7.3%. Men were 81.0%, those who are aged from 26 to 30 were 39.0%, Graduatee from high school 92.7%, Christians 56.3%, unmarried 55.4% and salary from 600,000 Won to 800,000 Won 53.8% averaging monthly payment 669,810 Won. As for their residence, those who resided over 3 years were 31.9% and the illegal residence reached 77.4%. As for Korean language, those who speak in middle level were 5.6%. 2) As for kind of work and circumstances, manufacturing was 81.1%, 4 off-days per month 72.2% and 9-10 working hours per day 42.1%. As for accommodation, residence in fabric was 62.6% and one or two members as roommate 40.2%. 3) The characteristics of health behavior showed that 89.4% of migrant workers had 3 meals, 70.9% of them did not drink alcohol, 73.5% of them did not smoke. 4) As a characteristic of health status, 71.8% of them perceived of their health. 76.1% thought that they had no illness before coming Korea. Among them who recognized their illness, those who had problem in circulatory system was 35.3%, respiratory system ENT 19.1% and nervous system 19.1%.66.2% of those having illness had already had sickness when coming to Korea. 5) During last one month, 79.2% of them were known as ones having no illness. Among the sick, those who had problem in circulatory system was 31.6%, nervous system 23.7% and respiratory system 21.1%. 60.3% of the sick were not cured at that time. 6) Sorting the symptom of those who visited free medical check up, dental care was 24.2%, orthopedic 14.0% and digestive system 13.8%. Teethache was 34.4%, stomach problem 11.6%, upper respiratory inflammation 10.2% and back pain 5.9%. Averagely they visited free medical check up 1-2 times. According to symptom, epilepsy 25.5 times, heart and vascular disease 9 times, constipation 2.8%, neurosis 2.38 times and stomach problem 2.34 times. 7) The most frequently visited medical service by migrant workers was hospital. The most mentioned reason was good healing as 36.3%. The medical service satisfied migrant workers mostly was hospital as 64.3%. The reason of satisfaction was also good healing as 45.9%. 8) 77.2% of respondents did not spend money for medical check. Average monthly medical cost was 25,100 Won, 3.7% of income. Those who had no medical security was 73.4%. In their case, 67.7% got discount from hospital or support from working place and religious organization. 9) As for the difference of medical utilization according for the characteristics of migrant workers, legal workers and no-Korean speaker used hospital more frequently. 10) Those who were satisfied most of all with the service of hospital were female workers, hinduists and buddhists, legal workers or manufacture workers. 11) Christians, those who have 3 meals or recognize themselves as healthy ones mostly had no illness. As a result, the most of migrant workers in Korea are from Asia. They are good educated but are working in manufacturing and illegal. Their average income is under 700,000 Won which in not enough for medical cost. They have no medical security and medical fee is supported by religious organization or discounted. Considering these facts the medical policy by government is to be established.

• Journal of Aquaculture
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• v.1 no.1
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• pp.67-73
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• 1988

A growth experiment of tilapia (offsprings of the hybrid between Oreochromis niloticus and O. mossambicus) under different dissolved oxygen levels in the recirculating water system was conducted at the Fish Culture Experiment Station of the National Fisheries University of Pusan from February 4 to March 5, 1986. Six tanks with a capacity of $1.8m^3$ of water each were used under the same condition of water parameters except for dissolved oxygen levels which were designated to maintain at 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg/$\iota$. Each tank was stocked with 90 kg of fish each averaging 64 to 69 grams. The average water temperature during the course of the experiment was $22.5^{\circ}C$. The results obtained are summarized as follows: The food conversion efficiencies were very good, being 1.05-1.11 at 3.5, 3.0, 2.5 and 2.0 mg/$\iota$ DO levels without any significant differences among them, but at 4.0 mg/$\iota$ the F. C. was 1.39 and at 1.5 mg/$\iota$ it was 1.61 being very poor compared with the others. The daily growth rate performance was best at 3.5 mg/$\iota$ dissolved oxygen level followed by 3.0 and 2.5 mg/$\iota$ with slight differences while at 4.0 and 2.0 mg/$\iota$ DO levels the growths were significantly poor, and at 1.5 mg/$\iota$ DO level it was extremely poor. In 1.5 mg/$\iota$ group, the fish did not accept feed vigorously and after feeding the fish usually concentrated around the inflow point showing oxygen deficiency response. While at 4.0 mg/$\iota$ high feeding rates tended to waste significant amounts of feed while eating and led to water deterioration, and above these levels the results is considered to lead to a waste of energy with uneconomical performance. On the other hand, at and below 2.0 mg/$\iota$ DO level the tilapia certainly showed a poor growth performance. The experiment indicates that the DO range of 2.5$\~$3.5 mg/$\iota$ is the optimum level for the good growth performance.

• Progress in Medical Physics
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• v.20 no.4
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• pp.290-297
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• 2009

In case of radiation treatment using small field high-energy photon beams, an accurate dosimetry is a challenging task because of dosimetrically unfavorable phenomena such as dramatic changes of the dose at the field boundaries, dis-equilibrium of the electrons, and non-uniformity between the detector and the phantom materials. In this study, the absorbed dose in the phantom was measured by using an ion chamber and a diode detector widely used in clinics. $GAFCHROMIC^{(R)}$ EBT films composed of water equivalent materials was also evaluated as a small field detector and compared with ionchamber and diode detectors. The output factors at 10 cm depth of a solid phantom located 100 cm from the 6 MV linear accelerator (Varian, 6 EX) source were measured for 6 field sizes ($5{\times}5\;cm^2$, $2{\times}2\;cm^2$, $1.5{\times}1.5\;cm^2$, $1{\times}1\;cm^2$, $0.7{\times}0.7\;cm^2$ and $0.5{\times}0.5\;cm^2$). As a result, from $5{\times}5\;cm^2$ to $1.5{\times}1.5\;cm^2$ field sizes, absorbed doses from three detectors were accurately identified within 1%. Wheres, the ion chamber underestimated dose compared to other detectors in the field sizes less than $1{\times}1\;cm^2$. In order to correct the observed underestimation, a convolution method was employed to eliminate the volume averaging effect of an ion chamber. Finally, in $1{\times}1\;cm^2$ field the absorbed dose with a diode detector was about 3% higher than that with the EBT film while the dose with the ion chamber after volume correction was 1% lower. For $0.5{\times}0.5\;cm^2$ field, the dose with the diode detector was 1% larger than that with the EBT film while dose with volume corrected ionization chamber was 7% lower. In conclusion, the possibility of $GAFCHROMIC^{(R)}$ EBT film as an small field dosimeter was tested and further investigation will be proceed using Monte Calro simulation.

• Journal of Animal Science and Technology
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• v.50 no.6
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• pp.819-830
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• 2008

The object of this study was to investigate different levels of extruded rice product(Nutri-RS®) supplementation as an alternative to lactose on growth performance, diarrhea score, fecal E.coli and volatile fatty acid(VFA) in weaning pigs. Treatments were 1) Control(basal), L3(basal+3% extruded rice product), L6(basal+6% extruded rice product). The control diet in Phase I and Phase II contained 16 and 9% of lactose, respectively. For the feeding trial, a total of 81 crossbred pigs, averaging 7.56±1.18 kg body weight, were allotted to three treatments in three replicates with nine pigs per pen by RCBD. The experimental period was total 5 weeks. During the whole experimental period, there were no significant differences in growth performance, diarrhea score, fecal volatile fatty acid concentration among all treatments. Although there were no significant differences, pigs fed diet of L6 tended to show higher BW and ADG, ADFI, and fecal volatile fatty acid concentration compared to other treatments. Treatment L6 showed the lowest fecal E. coli count among all treatments(P<0.05). These results suggested that inclusion of extruded rice product has similar performance a with 6% of lactose in diet for weaning pigs and reduce approximately 9% production cost of weaning pig's diet. Therefore, extruded rice product could be utilized as an alternative feed ingredient to lactose in weaning pig’s diet.

• Journal of Aquaculture
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• v.19 no.4
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• pp.275-280
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• 2006

Effect of the various sources of dietary additives on growth, body composition and shell color of abalone Haliotis discus hannai was investigated for 16 weeks. Forty juvenile abalone averaging 13.5 g were randomly stocked into 21 of 50 L plastic rectangular containers each. Eight kinds of additives were prepared for this study: four commercially available microalgae [Haeatococcus (Hae), Isochrysis galbana (Iso), Shizochytrium (Sch) and Spirulina (Spi)], three crustacean meals [krill meal (KM), shrimp head meal (Shm) and red crab meal (Rcm)], and green tea by-product (Gre). In addition, dry sea tangle (Dst), Laminaria japonica, as a control, was prepared. Casein, dextrin and a mixture corn oil and fish oil was protein, carbohydrate and lipid sources, respectively, in the experimental diets. The 2% each additive was included into the experimental diets. The experimental diets were fed to abalone once a day at the ratio of $1.5{\sim}2.0%$ total biomass of abalone with a little leftover throughout the 16-week feeding trial. Survival of abalone was not significantly (P>0.05) affected by the experimental diets. However, weight gain of abalone fed the all experimental diets containing the various sources of additives was significantly (P<0.05) higher than that of abalone fed the Dst diet. Weight gain of abalone fed the Spi diet was highest and Shi, KM and Iso diets in order. Shell length and the ratio of soft body weight to body weight of abalone was not significantly (P>0.05) affected by the experimental diets. However, shell width of abalone fed the all experimental diets containing the various sources of additives was significantly (P<0.05) higher than that of abalone fed the Dst diet. The shell color of abalone fed the Spi diet was improved the most distinctively and similar to that of natural abalone. Therefore, it can be concluded that the experimental diets with the various sources of additives (microalgae and crustacean meals) was effective to improve growth of abalone and dietary inclusion of Spirulina was most effective to improve shell color of abalone.

• Journal of Aquaculture
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• v.19 no.4
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• pp.247-253
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• 2006

This study was conducted to investigate the effects of dietary supplementation of ${\beta}-1,3$ glucan on growth and immune responses in juvenile olive flounder, Paralichthys olivaceus fed the white fish meal based diets for 6 weeks. Five experimental diets supplemented with ${\beta}-1,3$ glucan at 0, 0.01, 0.025, 0.05, 0.1 % (Control, $G_{0.01},\;G_{0.025},\;G_{0.05}\;and\;G_{0.1}$, respectively) of diet on a dry-matter basis. Five experimental diets were formulated to be isonitrogenous and isocaloric to contain 50.0% crude protein and 16.7 kJ available energy $g^{-1}$. Fish averaging $3.2{\pm}0.1\;g\;(mean{\pm}SD)$ were randomly distributed in each aquarium as triplicate groups of 15 fish. Weight gain (WG, %), specific growth rate (SGR, %), and feed efficiency (FE, %) of fish fed $G_{0.1}$ diet were found significantly higher than those of fish fed Control, $G_{0.01},\;G_{0.025}\;and\;G_{0.05}$ diets (P<0.05). However, there was no significant difference among the fish fed control, $G_{0.01},\;G_{0.025}$. Chemiluminescent responses (CL) of fish fed $G_{0.1}$ diet were significantly higher than those of fish fed the other diets. Serum lysozyme activities of fish fed $G_{0.05}$ and $G_{0.1}$ diets were higher than those of fish fed control, $G_{0.025}$ and $G_{0.05}$ diets. Fish fed $G_{0.1}$ diet showed a significantly lower cumulative mortality than did fish fed control diet throughout the challenge test (P<0.05). These results suggested that based on growth rate, feed efficiency, non-specific immunity and protection against microbial infections the optimum dietary ${\beta}-1,3$ gulcan could be greater than 0.05% but less than 1.0% in juvenile olive flounder, Paralichthys oilvaceus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.712-726
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• 1994

Feeding trials were conducted to determine the essentiality of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and to compare the efficiency between EPA and DHA for juvenile Korean rockfish. Fish averaging 2.1 g were fed experimental diets containing different levels of EPA or DHA, and different combinations of EPA and DHA in two separate experiments. Graded levels ($0.0{\sim}l.75\%$) of dietary EPA or DHA as ethyl esters were substituted for a part of the $8\%$ beef tallow in the basal diet. After 5 weeks of the experimental period, weight gain, chemical composition of whole body, protein and lipid retention efficiency, hepatosomatic index, and fatty acid composition of liver were measured. Daily growth rate and feed efficiency were the lowest in fish fed the diets without EPA arid DHA. These responses were effectively improved by increasing EPA or DHA in the diets up to $1.0\%$ levels, and then reached a plateau between 1.0 and $1.75\%$ levels of either EPA or DHA. Protein and lipid retention efficiency were also improved with the high levels of dietary EPA or DHA. DHA was superior to EPA at the same level of each in weight gain, feed efficiency, and protein and lipid retention efficiency. Hepatosomatic index tended to decrease with increase of the dietary EPA or DHA levels. Lipid contents of whole body were increased with levels of EPA or DHA in the diets. Dietary EPA and/or DHA levels affected directly the fatty acid composition of liver polar lipid. EPA or DHA in the liver polar lipid were increased with levels of dietary EPA or DHA, respectively, whereas those in nonpolar lipid were not affected by the dietary levels of EPA and/or DHA. These finding indicate that either of the EPA or DHA is essential for normal growth of Korean rockfish, and the essential fatty acid requirement is $1.0\%$ of EPA and/or DHA in the diet. DHA is superior to EPA as essential fatty acid, and the dietary EPA/DHA ratio of less than 1.0 may be adequate for normal growth of Korean rockfish fed a diet enough n-3HUFA (EPA and DHA).