• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.45-45
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• 2017

The Indian meal moth, Plodia interpunctella, is one of the most important pests of stored food in the food processing industry worldwide. To control the Indian meal moth, methyl bromide, phosphine, high carbon dioxide, sulfuryl fluoride and plant essential oil fumigation have been considered. However, these treatments have disadvantages. For example, depleting the ozone layer, showing resistance in insect, low control efficacy or need high cost for treatment. Chlorine dioxide ($ClO_2$) is strong disinfectant and insecticide. The gas caused a malfunction in enzymes. The oxidative stress induced by $ClO_2$ gas treatment damaged to a physiological system and all life stages of P. interpunctella. The gaseous $ClO_2$ is a convincing alternative to methyl bromide for controlling P. interpunctella. The gaseous $ClO_2$ was generated by a chlorine dioxide generator (PurgoFarm Co., Ltd., Hwasung, Korea). It generated highly pure $ClO_2$ gas and the gas blown out through a vent into a test chamber. Gas entry to the chamber was automatically controlled and monitored by a PortaSene II gas leak detector (Analytical Technology, Collegeville, PA, USA). The properly prepared eggs, larvae, pupae, and adults of P. interpunctella were used in this experiment. Data were analyzed using SAS 9.4. Percentage data were statistically analyzed after arcsine-root transformation. Analysis of variance was performed using general linear model, and means were separated by the least significant difference test at P < 0.05. Fumigation is an effective management technique for controlling all stages of P. interpunctella. We found that $ClO_2$ gas treatment directly effects on egg, larvae, pupae and adults of P. interpunctella. The gas treatment with proper concentration for over a day achieved 100 % mortality in all stages of P. interpunctella and short time treatment or low concentration gas treatment results showed that the egg hatchability, pupation rate, and adult emergency rate were lowered compare with untreated control. Also, abnormal pupae or adult rate were increased. Gaseous $ClO_2$ treatment induced insecticidal reactive oxygen species (ROS), and it resulted in fatal oxidative stress in P. interpunctella. Taken together, these results showed that exposure proper concentration and time of the gas control all stages of P. interpunctella by inducing fatal oxidative stress. Further studies will be required to apply the gas treatment under real-world condition and to understanding physiological reaction in P. interpunctella caused by oxidative stress.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1566-1575
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• 2014

In this study, we have investigated the effect of perceived health status, sleep, depression and pain on quality of life by Gender in Community-dwelling Older Adults. A cross-sectional descriptive study was conducted with a survey of elderly aged 65 years or older that registered in the health care center located in J city from december 20, 2012 to february 15. Data were analyzed with descriptive statistics, t-test, ANOVA. Pearson correlation coefficients and multiple regression analysis using the SPSS Win 18.0 program. The result of perceived health status on average $9.89{\pm}2.21$ points, sleep $39.72{\pm}8.79$ points, depression, $7.13{\pm}7.54$ points, pain $5.37{\pm}1.90$ points and quality of life, the average was $7.61{\pm}2.25$ points. Perceived health status of low-income that perceived health status, sleep, and pain. explained 44.6% of variance in their quality of life. Based on the findings of the study, low-income elderly in home in order to improve the quality of life of the systematic development of intervention programs for health care and nursing needs to be applied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.182-188
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• 2017

This study analyzes several factors of good instruction that have been studied by precedent studies as well as the dominated perspective of teaching that validates the value of good instruction. For this purpose, the authors explore an understanding of the perspective that lessons ought to pursue. The authors examine the difference in the dominated perspective of good instruction of pre-service teacher and teachers through the study methodology of chi-square, one-way analyses of variance, and post-hoc test. The research subjects were enrolled students and graduates of the Department of Early Childhood Education at colleges in Seoul and the Capital area. The TPI that had been objectively indexed with comprehensive understandings and viewpoints of good instruction was also applied. The study result shows that high schools' dominated perspective is "nursing" and colleges' is "apprenticing", regardless of the kind of school. The article discusses the perspective of good instruction by comparing the results of domestic and foreign studies and this study. Some ideas were suggested for further research.

• International Journal of Highway Engineering
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• v.4 no.3 s.13
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• pp.43-49
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• 2002

Asphalt pavements have to perform under the conditions of heavily-loaded vehicles due to the industrialization and large temperature variance between the summer and the winter. Due to these factors, a characteristics change of early permanent deformation becomes a big issue, and to remedy this problem many research to use modified asphalt are being widely conducted. However, most of the modified asphalt is being paved after milling the surface course and applying tackcoating, and it is being used mostly for the repair and maintenance purpose rather than pavement of new national road. The purpose of this investigation is to obtain some fundamental data for the evaluation of the performance and long-term performance of the construction material mixtures by the laboratory test and field experiments. For the field experiment, 200m of two-lanes national road, that is being paved for the new national road under the direction of Pusan Regional Construction Management Office, was paved with SBS PMA and PSMA asphalt mixtures, which are an modified asphalt mixtures used for the surface course, on top of the base course paved with other modified asphalt mixtures. The remaining section of the new national road was paved with dense grade mixture. The laboratory tests assessed and analyzed the mixture characteristics by Marshall's stability test, strength tests and wheel-tracking test. On the basis of the evaluation result of the temperature control and roughness of the newly constructed road at the field experiment site, it is desired to evaluate and identify the most economic modified asphalt mixtures by long-term performance evaluation and LCC(Life Cycle Cost) analysis in order to apply the test result to the design of new road construction in the future.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.49-60
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• 2008

The aim of this study was to evaluate the variability of the blood.breath ratio (BBR) value and to rationalize the determination of ethanol in breath for evidential sobriety testing. In the experiment forty eight healthy persons, 24 men and 24 women, took part. The experiment included the experimental condition such as sex(2),the type of alcoholic beverage(2; soju, whisky), the type of food(2;kimchi stew, pork belly) and the amount of ethanol consumed(2; 0.35g/kg, 0.70g/kg, based on body weight ) according to 24 factorial design by orthogonal arrays. Breath and blood sample were taken each 8 times and 5 times after the end of drinking. The blood and breath alcohol measurements were highly correlated (r = 0.973). The Results of four way analyses of variance revealed a significant 'the type of food' effect for maximum BrAC (F (1, 43) =5.1, pp<.029), but no significant effect in the type of alcoholic beverage and sex. The overall blood/breath ratio (${\pm}$ SD) was 2295${\pm}$403 and the 95% confidence interval were 1489 and 3101. In spite of these variations, at this time, it seems to be reasonable that apply 2100:1 conversion factor to breathalyzers, because most of the subjects showed the blood.breath ratio of over 2100:1 at least 30 minutes or more passed from the time of drinking as shown in this study.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.313-323
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• 2017

Objectives: This study aimed to assess exposure to black carbon(BC) among forklift operators and to identify environmental and occupational factors influencing their BC exposure. Methods: We studied a total of 23 forklift operators from six workplaces manufacturing paper boxes. A daily BC exposure assessment was conducted during working hours from January to April 2017. A micro-aethalometer was used to monitor daily BC exposure, and information on work activities was also obtained through a time-activity diary(TAD) and interviews. BC exposure records were classified into four categories influencing BC exposure level: working environment, workplace, forklift operation, and job characteristics. Analysis of variance(ANOVA) was used to compare average BC exposure levels among the four categories and the relationships between potential factors and BC exposure were analyzed using a multiple linear regression model. Results: The operators' daily exposure was $12.9{\mu}g/m^3$(N=9,148, $GM=7.5{\mu}g/m^3$) with a range: $0.001-811.4{\mu}g/m^3$. The operators were exposed to significantly higher levels when they operate a forklift in a room ${\leq}20,000m^3$($AM=12.3{\mu}g/m^3$), in indoor workplaces($AM=16.3{\mu}g/m^3$), when they operate a forklift manufactured before 2006 ($AM=13.2{\mu}g/m^3$), a forklift with a loading limit of four-tons($AM=27.1{\mu}g/m^3$), with a roll and bale type clamp($AM=17.1{\mu}g/m^3$), and with no particulate filter($AM=15.7{\mu}g/m^3$). Conclusions: Occupational factors including temperature, smoking, season, daytime, room volume($m^3$), location of operating, and manufacturing era and model of forklift influenced the BC exposure of forklift operators. The results of this study can be used to minimize the BC exposure of forklift operators.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.131-137
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• 2014

Purpose: This study examined the efficiency and wear of periodontal instrument sharpening using aluminum oxide stones with different levels of roughness. Materials and Methods: Thirty new No. 9-10 Gracey curets were used in this study. All curets had become dull after scaling and root planing. After similar blunting, the instruments were divided randomly into three groups (240, 600, 800 grit) containing 10 curets each. The stones were applied correctly to the lateral surface of each curet to maintain the $70-80^{\circ}$ angle. After resharpening, sharpness of the curets was examined by an optical microscope. After 20, 40, 60, and 80 strokes, the wear was measured at 1 mm and 2 mm from the tip of the cutting edge using a digital caliper. The data was analyzed statistically using analysis of variance (ANOVA) with repeated measures, 2-way ANOVA, and a Fisher's exact test. Results: The degree of sharpness increased significantly (P < 0.001) as the number of sharpening strokes grew for all stones. A comparison of the degree of sharpness on the same number of strokes showed that the 240 grit group significantly excelled the other groups on 5 and 10 strokes, respectively (P < 0.001). The mean wear showed no statistically significant difference among the groups (P > 0.05). Conclusion: The efficiency of Gracey curet resharpening was enhanced with more coarse stones, though we should consider the wear of the instrument during resharpening.

• Physical Therapy Korea
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• v.16 no.2
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• pp.67-76
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• 2009

In order to prevent upper extremity musculoskeletal disorders, effective keyboard selection is an important consideration. The aim of this study was to compare upper extremity muscle activity according to transverse plane angle changes during vertical keyboard typing. Sixteen healthy men were recruited. All subjects had a similar typing ability (rate of more than 300 keystrokes per minute) and biacromion and forearm-fingertip lengths. Four different types of keyboard (vertical keyboard with a transverse plane angle of $60^{\circ}$, $96^{\circ}$, or $120^{\circ}$, and a standard keyboard) were used with a wrist support. The test order was selected randomly for each subject. Surface electromyography (EMG) was used to measure upper extremity muscle activity during a keyboard typing task. The collected EMG data were normalized using the reference contraction and expressed as a percentage of the reference voluntary contraction (%RVC). In order to analyze the differences in EMG data, a repeated one-way analysis of variance, with a significance level of .05, was used. Bonferroni correction was used for multiple comparisons. There were significant differences in the EMG amplitude of all seven muscles (upper trapezius, middle deltoid, anterior deltoid, extensor carpi radialis, extensor carpi ulnaris, flexor carpi radialis, and flexor carpi ulnaris) assessed during the keyboard typing task. The mean activity of each muscle had a tendency to increase as the transverse plane angle increased. The mean activity recorded during all vertical keyboard typing was lower than that recorded during standard keyboard typing. There was no significant difference in accuracy and error scores; however, there was a significant difference between transverse plane angles of $60^{\circ}$ and $120^{\circ}$ with regard to comfort. In conclusion, a vertical keyboard with a transverse plane angle of $60^{\circ}$ would be effective in reducing muscle activity compared with vertical keyboards with other transverse plane angles.

• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.97-104
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• 2006

This study was conducted to investigate effect of temperature and NaCl on the seed germination and water absorption of Thuja orientalis. Seeds were treated with 0, 500, 1,000, 2,000 and 4,000ppm of NaCl and placed in different chambers at 15, 20, 25 and $30^{\circ}C$, respectively. And seed properties and relative water absorptions were analyzed. Germination decreased with the increase of both temperature and NaCl concentration, and especially the difference was obvious at $30^{\circ}C$. Dormancy and mortality increased with the increase of temperature in non-NaCl treatment. Two-way analysis of variance showed significant effects of temperature, NaCl concentration and interaction between temperature and NaCl concentration (p<0.001). Mean germination time increased with the increase of NaCl concentration at 15, 20 and $25^{\circ}C$ but decreased at $30^{\circ}C$ because the seeds were mortal by NaCl high concentration, Germination speed and germination performance index decreased with the increase of NaCl concentration. Those represented decreasing tendency with NaCl concentration but high positive correlation with germination. Relative water absorption decreased with the increase of NaCl concentration and represented high values at $15^{\circ}C$, and showed high positive correlations with germination, germination speed and germination performance index. It was reported that the high temperature and salinity were inhibitive factors of seed germination of Thuja orientalis.

• Journal of Life Science
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• v.22 no.9
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• pp.1173-1179
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• 2012

The importance of genetic stability and bio-safety in the environment has recently been recognized for many (genetically modified) GM plants. This study evaluated the GM safety of transgenic rice and its environmental variance. Data on agronomic characters and principal component were collected for vitamin A-enriched GM rice and four check cultivars in a large GM field trial during 2009-2011. The cultivation environment was a large GM field and a greenhouse. In this experiment, there was no significant difference between the agronomic characters of the GM rice and those of a donor plant, 'Nagdong'. In terms of grain characteristics, the appearance and physicochemical characteristics of the GM rice and those of the donor plant were similar. However, the grain of the GM rice developed a white core and a white belly when planted in the greenhouse. The type and distribution of dominant weed species were not different in the GM rice and the 'Nagdong'. In addition, gene flow was not detected in the dominant weed species based on PCR analysis.