• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.725-732
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• 2012

There is relatively high vulnerability of soil erosion in slope highland agriculture due to a reclamation of mountain as well as low surface covering during early summer with high rainfall intensity. Especially, in soybean cultivation, soil disturbance by conventional tillage and exposure of topsoil at the early stage of soybean have intensified soil loss. The aim of this study was to evaluate various surface covering methods for reducing soil loss in highland soybean cultivation. The experiment was conducted in 17% sloped lysimeter ($2.5m{\times}13.4m$) with 8 treatments. Amount of runoff water and eroded soil, and soybean growth were investigated. Surface covering through sod culture and plant residue showed 3.4~45.0 runoff water amount with $177{\sim}2,375m^3\;ha^{-1}$ compared with control ($5,274m^3\;ha^{-1}$). And the amount of eroded soil was also reduced by 95% in surface covering treatment with $0.02{\sim}1.94Mg\;ha^{-1}$ than control with $40.72Mg\;ha^{-1}$. Yields of soybean pod showed $0.3Mg\;ha^{-1}$ in rye sod culture, $1.3Mg\;ha^{-1}$ in Ligularia fischeri var. spiciformis Nakai, $0.7Mg\;ha^{-1}$ in Aster koraiensis Nakai, $0.2Mg\;ha^{-1}$ in red clover and $2.0Mg\;ha^{-1}$ in non-covering, on the other hand, covering with cut rye showed $3.8Mg\;ha^{-1}$. Conclusively, covering the soil surface with cut rye were beneficial for reduction of soil loss without decreasing soybean yield in highland sloped fields.

• Journal of dental hygiene science
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• v.9 no.1
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• pp.137-143
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• 2009

The purpose of this study was to survey the cause factor and degree of stress experienced by second and third grade students of dental hygiene department in Gyeong-nam province and Ulsan Metropolitan city who were finished two weeks public health center training and four weeks dental hospital and local dental clinical training. It was to provide basic data and improve the problem of clinical training program. 1. In respect of their motives of choosing the hygiene department, 64.8% in second grade and 62.2% in third grade of those respondents cite guarantee of getting a job as main reason. In respect of the satisfaction for major field, 29.6% of second grade and 73.3% of third grade respondents were satisfied. 2. In the satisfaction for clinical training in public health center, 46.3% of second grade and 46.7% of third grade respondents were satisfied. In the satisfaction for clinical training in local dental clinic and hospital, 50.9% of second grade and 66.7% of third grade respondents were satisfied. 3. In the respect of major factor to feel stress in clinical training in public health center, the relation of school practice program and clinical training in public health center, 50.5% of respondents was felt stress because of the difference between school practice program and field condition was exist. 4. In the respect of major factor to feel stress in local dental clinic and hospital training, the relation of school practice program and clinical practice in public health center, 54.5% of respondents were felt stress. 62.1% of respondents were felt stress because of the difference between knowledge and practice. 58.1% of respondents were felt stress because of the difference between school practice program and field condition was exist. 50.5% of respondents were felt stress because of the lack of knowledge in related fields. As the above results, it is necessary to develop clinical practice program that is to increase satisfaction and provide motivation in oder to reduce the stress during clinical training.

• Journal of the Korean Geotechnical Society
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• v.28 no.5
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• pp.13-25
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• 2012

Ground anchor method is one of the most popular reinforcing technology for slope in Korea. For the health monitoring of slope which is reinforced by permanent anchor for a long period, monitoring of the tension force of ground anchor is very important. However, since electromechanical sensors such as strain gauge and V/W type load cell are also subject to long-term risk as well as suffering from noise during long distance transmission and immunity to electromagnetic interference (EMI), optical FBG sensors embedded tendon was developed to measure strain of 7-wire strand by embedding FBG sensor into the center king cable of 7-wire strand. This FBG sensors embedded tendon has been successfully applied to measuring the short-term anchor force. But to adopt this tendon to long-term monitoring, temperature compensation of the FBG sensors embedded tendon should be done. In this paper, we described how to compensate the effect in compliance with the change of underground temperature during long-term tension force monitoring of ground anchors by using optical fiber sensors (FBG: Fiber Bragg Grating). The model test was carried out to determine the temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon. The determined temperature sensitivity coefficient ${\beta}^{\prime}=2.0{\times}10^{-5}/^{\circ}C$ was verified by comparing the ground temperatures predicted from the proposed sensor using ${\beta}^{\prime}$ with ground temperatures measured from ground thermometer. Finally, temperature compensations were carried out based on ${\beta}^{\prime}$ value and ground temperature measurement from KMA for the tension force monitoring results of tension type and compression type anchors, which had been installed more than 1 year before at the test site. Temperature compensated tension forces are compared with those measured from conventional load cell during the same measuring time. Test results show that determined temperature sensitivity coefficient (${\beta}^{\prime}$) of FBG sensors embedded tendon is valid and proposed temperature compensation method is also appropriate from the fact that the temperature compensated tension forces are not dependent on the change of ground temperature and are consistent with the tension forces measured from the conventional load cell.

• Journal of Korean Home Economics Education Association
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• v.29 no.4
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• pp.117-131
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• 2017

This study was performed to analyze education contents related to milk in current home economics textbooks of middle school, and to investigate intake status, consumption behaviors, perception and nutritional knowledge of milk and dairy products among 364 middle school students in Gongju for improvement of milk education in home economics subjects and milk intake of adolescents. As a result, education contents of milk and dairy products in home economics textbooks currently applied in middle school were major nutrients, consumption method for balanced diet, and selection and storage of milk and dairy products, thus it tended not to match current food trend. Only 30.5% of subjects met 2 cups of milk a day, the recommended level. The main reason for drinking milk was to 'be taller' and 'to quench thirst' and there was a difference by gender(p<0.01). The rate of not participating in school milk program was 23.1% of total and its satisfaction was moderate. The most popular dairy products by subjects were ice cream, followed by yogurt and cheese, and the choice of milk was focused on 'taste' or 'expiration date'. The rate of knowing certification mark of K-MILK was low at 28.8%, and most subjects knew as 'domestic milk use'. In home economics class, experience-based learning such as cow ranch experience was the most preferred instruction method for milk followed by laboratory practice and lecture, and there was a difference by gender(p<0.001). Perception degree of milk and dairy products was moderate and male subjects were more positively perceived than female subjects(p<0.01). Nutritional knowledge level of milk and dairy products was moderate and female subjects were higher than male subjects(p<0.01). Therefore, education contents of milk and dairy products of home economics textbooks of middle school should be centered on real life in accordance with food trend, and applied student participation-based instruction methods such as experience-based learning. In addition, it is necessary to enhance taste and merchandise of milk and to provide them with preferred milk and dairy products in school milk program for improvement of milk intake of adolescents.

• Journal of The Korean Association For Science Education
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• v.32 no.5
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• pp.805-822
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• 2012

The purpose of this study was to explore the patterns of group model development about blood flow in the heart and reasoning process by small group interaction. The subjects were 14, 8th graders in a Science Gifted Center. The group discussion was made possible by using triggering questions that can be answered based on experiences of hands-on activities such as a siphon pump analogy model activity and a dissection of pigs' hearts. Despite participating in same activities, the groups showed different model development patterns: unchanged, persuasive, and elaborated. Due to the critical revising, the group's explanatory model was elaborated and developed in the added and elaborated pattern. As critical revising is a core element of the developing model, it is important to promote a group interaction so that students become critical and receptive. The pedagogical analogy model and conflict situation enabled students to present elaborated reasoning. The Inquiry activity with the pedagogical analogy model promote students' spontaneous reasoning in relation to direct experience. Therefore offering a pedagogical analogy model will help students evaluate, revise and develop their models of concerned phenomena in science classroom. Conflict situation by rebuttal enable students to justify more solid and elaborate a model close to the target model. Therefore, teachers need to facilitate a group atmosphere for spontaneous conflict situation.

• Korean Journal of Poultry Science
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• v.30 no.1
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• pp.29-34
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• 2003

It has been well documented that white egg layers are far more resistant to fowl typhoid than the brown egg layers. In Korea, however, most consumers prefer brown eggs to white ones. Therefore, a study was conducted to Produce fowl typhoid-resistant crossbred layers producing somewhat brown-colored eggs. Several crossbred strains were obtained from crossbreeding white egg lines (W) with brown egg lines (B). These crossbred layers (W${\times}$B) produced eggs with varying degrees of brown-colored shells between the white eggs obtained from W (White) and the brown eggs from B (Brown). Eggs from the peak stage of production were collected and their eggshell color values were measured. The mean eggshell color values of White and Brown were 81.9 and 36.4, respectively. Eggs from the crossbred lines (W${\times}$B) were collected, and their eggshell color values were measured to re-group these eggs according to their color. The mean eggshell color values of Trt-White, Middle, and Trt-Brown were 70, 60, and 50, respectively (Fig. 1). A total of 247 people living in Daejeon area, mainly housewives, took part in this survey. First, they were offered eggs with varying degrees of eggshell color in a paper egg-tray, together with a questionnaire. After they filled out the first questionnaire, they were instructed that the eggshell color has nothing to do with its nutritive value. In the second questionnaire, their preference on both eggshell color and price, i.e., purchasing will, were investigated. In the first questionnaire, the Brown (eggshell color lightness 36.4) were most preferred, and the Trt-white (eggshell color lightness 70) were least preferred. No statistical significance was detected between Brown and Trt-Brown, and White and Trt-White. In the second questionnaire, the trend was the same as in the first. Although no significant difference was found between Trt-Brown and Brown, however, the Trt-Brown were most preferred, surpassing the Brown. In conclusion, regardless of the nutritive values, the Korean consumers prefer brown eggs to white ones, and this trend could be changed gradually through consumer education.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.26-37
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• 1992

Fifty-five field experiments were conducted in order to find out some useful indices for the prediction of N-supplying capability(NSC) of soils under cultivation of corn in Pennsylvania over 3 years from 1986. Contents of $NO_3-N$, absorbance at 200 nm of the extract from soil with 0.01M $NaHCO_3$ were identified to be used as indices before planting. Methods for the estimation of organic nitrogen available later in the growing season(KCLA-N, PBBA-N, UV260 nm absorbance of $NaHCO_3$ extract) were not to be used as good indices individually, but when those are combined together with inorganic $NO_3-N$ showed a highly significant correlationship with the NSC. The year of an even distribution of rainfall, 1987, gave the highest significant correlationship between NSC and the indices. For soils of the same texture with slightly different physical properties, combined indices obtained from physico-chemical factors improved the degree of predictability when the grades of soil slope, depth of Ap were considered at the same time. More futher researches such as this need to be done before any conclusive result can be drawn.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.365-372
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• 2005

This study was carried out to investigate the Physiochemical Properties of loin and rump in the native horse meat from Jeju. In the analysis of chemical composition of loin and rump, the result showed $72.2\%\;and\;73.8\%$ in moisture content $20.1\%\;and\;21.2\%$ in crude protein, $2.42\%\;and\;3.08\%$ in crude Int and $0.13\%\;and\;0.14\%$ in crude ash respectively. Glutamic acid was 3,275mg/100g and 3,577mg/100g in loin and rump each and it had highest result in amino acid analysis. K content was 388.0mg/100g which showed highest result in mineral analysis and next contents were P>Na>Mg>Ca. Oleic acid had highest result in fatty acid composition which were $62.64\%\;and\;63.77\%$ in loin and rump respectively. Cholesterol content of loin and rump were 43.25 and 43.57 mg/100g but showed no significant differences to the part. pH of loin and rump were 5.60 and 5.75 which had no significant differences. Loin had Higher result than that of rump with no significant differences in WHC and springiness of texture analysis. Redness of rump was higher than that of loin. In the sensory evaluation, there were significant differences in the color and odor. Loin had higher result than that of rump in the overall palatability but showed no significant differences. With the result of this experiment native horse meat from Jeju could be understood as good meat resources.

• Economic and Environmental Geology
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• v.41 no.6
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• pp.645-655
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• 2008

The Cr(VI) concentrations at the shallow aquifer well (MPH-0-1) of the Moonpyung groundwater monitoring station were in the range of 0.5 to 3.1 mg/L exceeding 10 to 62 times the guideline for drinking-water quality, indicating continuous contamination. However, Cr was not detected at the deep bedrock well and the other subsidiary monitoring wells except for MPH-1 and 6. Cross-correlation analyses were conducted for rainfall and groundwater level time series, resulting in the mean time of recharge after precipitation events to be 5.6 days. For rainy season, the water level was raised and the Cr(VI) concentration was several times lower than that during dry season at well MPH-0-1 well. Correlation of the Cr(VI) concentration with the groundwater-level showed that the Cr(VI) reduction was closely related with the groundwater-level rise in the well. However, the groundwater level rise during high water season induced the lateral migration of the Cr(VI)-contaminated groundwater at well MPH-4. We enriched and isolated a chromium reducing bacteria, Enterobacter aerogenes, from the Cr(VI)-contaminated groundwater in the wells MPH-0-1 and MPH-1. The bacteria may play an important role for immobilizing Cr(VI) in the Cr(VI)-contaminated groundwater. Therefore, the migration of the contaminant (Cr(VI) must has been restricted because of the natural attenuation by microbial reduction of Cr(VI) in the groundwater. This research suggests that the bioremediation of the Cr(VI)-contaminated groundwater by the indigenous bacteria may be feasible in the Cr(VI) contaminated groundwater.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.273-281
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• 2012

This study was conducted for the establishment of the analytical method of pesticide residues in rice straw for 9 pesticides; etofenprox, tricyclazole, diazinon, edifenphos, propiconazole, carbaryl, carbofuran, 3-hydroxy carbofuran and 3-keto carbofuran and for the monitoring of these pesticides in rice straw for livestock feed in Korea. These pesticides were classified into 4 groups according to analytical instrument condition. Group 1 (HPLC-UVD1) included tricyclazole and etofenprox while group 2 (HPLC-UVD2) included propiconazole and edifenphos. Group 3 (HPLC-FLD) included carbaryl, carbofuran, 3-hydroxy carbofuran and 3-keto carbofuran. Group 4 (GC-NPD) included Diazinon. The dried rice straw samples were extracted with acetone and purified by liquid-liquid partition and solid phase extraction (SPE): Combination of Florisil SPE and amino-propyl SPE was used for group 1 and group 2, amino-propyl SPE for group 3, and Florisil SPE was for group 4. Recovery was in the ranged 70~110% and the limits of quantitation (LOQ) were lower than the half of maximum residue limits. Therefore this method was proved to be efficient for monitoring of these pesticides residue in rice straw. A total of 18 rice straw samples from 6 provinces in Korea in 2010 were analyzed using established method and, only 3-keto carbofuran was detected in one sample at concentration of 0.04 mg/kg.