• Journal of the Korean Society for Precision Engineering
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• v.12 no.5
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• pp.25-32
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• 1995

In highly automated milling process, in-process monitoring of the malfunction is indispensable to ensure efficient cutting operation. Among many malfunctions in milling process, chatter vibration deteriorates surface finish, tool life and productivity. In this study, the monitoring system of chatter vibration for face milling process is proposed and experimentally estimated. The monitoring system employs two types of sensor such as cutting force and acceleration in sensory detection state. The RMS value and band frequency energy of the sensor signals are extracted in time domain for the input patterns of neural network to reduce time delay in signal processing state. The resultes of experimental evaluation show that the system works well over a wide range of cutting conditions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.287-296
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• 2002

A field trial was conducted from May to November 2000 at four regions of Jeju province(Jeju, Seogwipo, Susan Seongsan and Keumak Hallim) to estimate adaptation, dry matter yield and nutrient value of kenafs(Everglades 41 and China Choung-pi 3) and a sorghum-sudangrass hybrid(Pioneer 947). Total dry matter(DM) yields of sorghum-sudangrass hybrid Pioneer 947, kenaf Everglades 41 and kenaf China Chong-pi 3 were 7,313, 4,653 and 5,238 kg/ha(P<0.05), respectively, kenaf China Chong-pi 3 being the highest. The region specific dry matter(DM) yields of Jeju, Seogwipo, Seongsan and Hallim area were 5,040, 5,663, 7,283 and 4,950kg/ha, respectively, showing that Seogwipo was the highest. Average DM yields of two kenaf varieties were 4,946, and 3,246 kg/ha for 1st time-cutting and 2nd time-cutting, respectively. The average dry matter(DM) yield of kenaf was significantly higher in the 1st time-cutting than the 2nd time. No significant difference in neutral detergent fiber(NDF) and acid detergent fiber(ADF) contents was found among three varieties. The average crude protein(CP) content of kenaf was higher than that of sorghum-sudangrass hybrid(P<0.05) and was higher in 2nd time-cutting than in 1st time-cutting(P<0.05). There were no significant difference in the heavy metal content of soil either between the sorghum hybrid and kenafs or between two kenaf varieties. In conclusion, the average dry matter(DM) yield of kenaf was lower than that of sorghum hybrid, Contrarily the crude protein(CP) content of kenafs was higher than that of the sorghum hybrid. The average dry matter(DM) yield of kenaf showed higher in 1st time-cutting than 2nd time-cutting, while the crude protein(CP) content of kenafs decreased with time.

• Research in Plant Disease
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• v.13 no.3
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• pp.164-169
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• 2007

Three kinds of disease occurring on ginseng leaves, such as grey mold, Alternaria blight, and anthracnose, started at the beginning of June, July, and August, respectively. The disease incidence was rapidly increased from the beginning of rainy season. To develop the control system with fungicides, 6 fungicides were selected and applied on ginseng at the indicated time. Calculating the control value by using the area under the disease progressing curve (AUDPC), the control activities of the supervised control system with fungicides were 61.7, 78.8 and 70.5% against grey mold, Alternaria blight, and anthracnose, respectively. The application of the mixture of carbendazim and diethofencarb on first of June was very important in control system with fungicides. If it was deleted in control system, control value was decreased against grey mold. In the case of Alternaria blight and anthracnose, the application of difenoconazole on July 18, and trifloxystrobin on August 7 were indispensible. If difenoconazole and trifloxystrobin were not applied on July 18, and August 7, the control activities against Alternaria blight and anthracnose, respectively, were decreased to 28.9% and 44.4%.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.285-292
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• 2020

Because the inner environment of greenhouse has a direct impact on crop production, many studies have been performed to develop technologies for controlling the environment in the greenhouse. However, it is difficult to apply the technology developed to all greenhouses because those studies were conducted through empirical experiments in specific greenhouses. It takes a lot of time and cost to develop the models that can be applicable to all greenhouse in real situation. Therefore studies are underway to solve this problem using computer-based simulation techniques. In this study, a model was developed to predict the inner environment of glass greenhouse using CFD simulation method. The developed model was validated using primary and secondary heating experiment and daytime greenhouse inner temperature data. As a result of comparing the measured and predicted value, the mean temperature and uniformity were 2.62℃ and 2.92%p higher in the predicted value, respectively. R² was 0.9628, confirming that the measured and the predicted values showed similar tendency. In the future, the model needs to improve by applying the shape of the greenhouse and the position of the inner heat exchanger for efficient thermal energy management of the greenhouse.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.63-70
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• 2012

To provide the basic information for preservation and reasonable management plan of Abies koreana population, vegetation structure and growing condition by altitude were analyzed. Six sites($400m^2$) were set up along the Georim valley in Mt. Jiri from 1,000m to 1,500m. The importance value of A. koreana in tree layer was the highest at 1,400m(site V) and 1,500m(site VI), and that of Quercus mongolica in the other site was high. In subtree layer, the importance value of A. koreana was the highest at site VI which located at 1,500m above the level of the sea. In DBH distribution, A. koreana population distributed evenly at all DBH class(below 10cm, 11-20cm, 21-30cm, above 31cm). Since 2000, the amount of tree-ring growth of A. koreana at site I, II, III, IV, V, and VI were 1.002, 0.996, 1.752, 1.850, 1.198, 0.984 mm/yr, which has decreased slowly in time for 2000, except site III.

• Journal of fish pathology
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• v.35 no.2
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• pp.195-203
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• 2022

This study was performed to delineate pharmacokinetic residue characteristics of lincomycin (LM) in olive flounder at low water temperature (13℃), and to examine whether LM is effective against main Gram-negative pathogens. It was observed that the times for residue declined below the maximal residue limit (0.1 mg/kg) in the muscle was, respectively, 32, 33 and 55 days following 10, 20 and 40 mg/kg intramuscular LM injections. The in vitro MIC value of LM against Edwardsiella piscida was higher than 256 ㎍/mL and against Vibrio harveyi 32 ㎍/mL when examined with several clinical isolates. These results suggest that the withdrawal time of LM should be more than 30 days in consideration of the 10 mg/kg employed as the regular clinical dose. It was also found that LM administered to treat streptococosis in olive flounder is not likely to be effective against some pathogenic Gram-negative bacteria.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.31-44
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• 2017

Pfiesteria piscicida is one of heterotrophic dinoflagellate having toxic metaboliges, and it is difficult to detect and quantify this dinoflagellate via light microscope due to small size and morphological similarity with Pfiesteria-like dinoflagellate (PLD) species. Alternatively, we developed quantitative real-time PCR assay based on EvaGreen and determined field accessibility throughout the investigation of distribution in the entire Korean coastal waters and population dynamics in Shihwa Lake. The P. piscicida-specific primers based on internal transcribed spacer 1 (ITS 1) were designed and the specificity of primers was confirmed by PCR with other genomic DNAs which have genetic similarity with target species. Through real-time PCR assay, a standard curve which had a significant linear correlation between log cell number and $C_T$ value ($r^2{\geq}0.999$) and one informative melting peak ($88^{\circ}C$) were obtained. These results implies that developed real-time PCR can accurately detect and quantify P. piscicida. Throughout the field applications of real-time PCR assay, P. piscicida was distributed in western (Mokpo and Kimje) and easthern (Gangneng) Korean coastal water even though light microscopy failed to identify P. piscicida. In the investigation of population dynamics in Shihwa Lake, the density of P. piscicida was peaked in June, July and August 2007 at St. 1 where salinity (${\leq}15psu$) was lower than the other 2 sites. In this study, we successed to develop EvaGreen bassed real-time PCR for detection and quantification of P. piscicida in fields, so this developed assay will be useful for various ecological studies in the future.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.190-197
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• 2008

The aim of this study was to determine the optimal cooking conditions in preparing jujube concentrates using various boiling times (5, 10, 15, 20 hours). The moisture contents of the concentrate samples ranged from 38.86 to 42.36%. Crude protein content was highest in the 15 hr-boiled concentrate, crude fat was highest in the 20 hr-boiled concentrate and both the 15 and 20 hr boiled concentrates had high crude fiber contents. There were no differences in color L- and a-values by boiling time; however, the b-value decreased with increasing boiling time. The pH levels of the concentrates ranged from 5.24 to 5.27, and the brix level increased with increasing boiling time. Glucose was the primary of free sugar in the concentrates and its highest level was 102.3 ${\mu}M$ in the 20 hr-boiled concentrate. The 15 hr-boiled concentrate had the highest electron donating ability to 46.68%. The total polyphenol contents of the concentrates ranged from 21.53 to 24.56%, in which the 15-boiled concentrate had the highest level (24.56%). In the sensory evaluation, the 15-hr-boiled concentrate again performed well, showing the highest overall acceptability scores. From these results, 15 hrs was the optimal boiling time for preparing jujube concentrate in terms of obtaining functional compounds and overall product acceptability.

• Food Science and Preservation
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• v.11 no.3
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• pp.299-303
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• 2004

Changes of concentration properties and shelf-life were investigated for preservation using Kalopanax pictus extract. We compared physicochemical (pH, sugar content, total acidity, color) and microbiological qualities of concentrated extract and extract with glucose added. At the result, pH of samples were increased as storage time increase. Whereas samples were not significantly different sugar content and total acidity as storage time. In Hunters color values, whiteness(L) and yellowness(b) value of samples tended to decrease during storage time but increase after 2 weeks of storage time. The samples were contaminated by microbial levels of 3.6$\times$10$^{1}$$\~$1.330$\times$10$^{3}$ CFU/g in total aerobic bacterial counts and negative in collforms. Samples at 2 $^{\circ}$Brix and 1 $\%$ glucose were effective for keeping the microbial population less than 2.0$\times$10$^{1}$ CFU/g.

• Korean Journal of Labor Studies
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• v.17 no.1
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• pp.297-323
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• 2011

Part-time jobs in Sweden are highly feminized yet are in fair conditions in terms of job security, earnings, and collective representation. Three points are considered to be important to understand why part-time work in Sweden carries such positive characteristics. First, the part-time work in Sweden is widely spread not as a result of employers' need for labor flexibilization but as means to enhance the work-life balance, a value pursued within a broader social policy package to change the breadwinner model. Second, discrimination against part-time workers is restrained in Sweden because the boundary between part-time and full-time is not conspicuous. Most of part-time jobs are occupied by regular workers who exert the right to part-time work, hence may go back to the full-time status any time. Third, the regulation on overtime work of part-time workers as well as full-time workers is strong. It is largely agreed among researchers that part-time work contributed greatly to an increase of female employment rate in Sweden. Since the 1970s, the increased availability of part-time jobs induced married women who used to be economically inactive to the labor market and maintained them to be economically active throughout the child rearing period. From the gender perspective, one may still raise issues regarding part-time work in Sweden such as persistent feminization and strong occupational sex segregation. However, the observed trend shows that the part-time work in Sweden has functioned more as a stepping stone to the full-time work for women than as a women's trap.