• Journal of Korean Home Economics Education Association
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• v.24 no.3
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• pp.89-100
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• 2012

The purposes of this study were to examine the overall tendency of perception of school environment and school adjustment in early adolescents during their transition from elementary to middle school. Also, examine the differences of adolescents' perception of school environment and school adjustment before and after entering secondary education. For this study, a total of 781 adolescents from middle school were asked to answer the questionnaire. And some objects of study, a total of 119 adolescents had answered in the same questionnaire content at the end of sixth grade of elementary school. The main findings were as followings. First, adolescents' perception of school environment during the transition to middle school was relatively good level, but perception of school safety appeared to be lower than average. Second, adolescents' school adjustment during the transition was comparatively good, particularly school life adjustment and school peer adjustment appeared to be above average. Third, there were significant positive relationships between perception of school environment and school adjustment. Fourth, adolescents' perception of school environment significantly decreased after they entered middle school, and significant differences were found in teacher support. Fifth, there were no differences in school adjustment before and after entering middle school, however school class adjustment and school life adjustment were significantly increased after the entrance into middle school.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1705-1711
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• 2001

Silage corn (Zea mays L) is grown extensively in livestock operations, and many managements focus on forage yield. This experiment was conducted at Seoul National University (SNU) Experimental Livestock Farm, Suwon in 1998. We determined the effect of planting date and harvest stage on forage yield and quality responses of corn hybrids (five relative maturity groups). The five maturity groups (100 d, 106 d, 111 d, 119 d and 125 d) were planted on 15 April and 15 May, and harvested at maturity stages (1/3, 1/2 and 2/3 kernel milkline). Whole plant dry matter (DM) and ear percentages had significant differences among corn hybrids. Ear percentages of early maturing corns (100 d and 106 d) were higher than for other hybrids. Ear percentage at the early planting date was higher than that at the late planting date for all corn hybrids. The DM and total digestible nutrients (TDN) yields of the 106 d and 111 d corn hybrids were higher than other hybrids, and the DM and TDN yields at the early planting date were higher than that at the late planting date. The acid detergent fiber (ADF) and neutral detergent fiber (NDF) percentages were greater for the late maturity corn hybrids. For plants of the early planting date, the ADF and NDF percentages were lower than for those of late planting date for hybrids. From the comparison among harvest stages, ADF and NDF percentages were decreased as harvest stage progressed. The TDN, net energy for lactation (NEL), and cellulase digestible organic matter of dry matter (CDOMD) were decreased as maturity of corn hybrid delayed. The TDN, NEL, and CDOMD values at the early planting date were higher than those at the late planting date among for corn hybrids. From the comparison among harvest dates, TDN, NEL, and CDOMD values were increased as harvest stage progressed. The correlation coefficient for DM percentage of grain at harvest with DM and TDN yields were 0.68*** and 0.76***, respectively. And the correlation coefficient for ear percentage with ADF, NDF, and CDOMD were -0.81***, -0.82*** and 0.73***, respectively. Our study showed differences of silage corn in forage production and quality resulting from hybrid maturity, planting date, and harvest stage. We believe that for the best silage corn, selection of the hybrid and best management practices are very important.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.380-391
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• 1992

This study was designed to evaluate a direct method of $^{99m}Tc$ labeling using $\beta-mercaptoethanol$ as a reducing agent, and to investigate whether $^{99m}Tc$ labeled specific monoclonal antibody against carcinoembryonic antigen (CEA-92) can be used for the scintigraphic localization of human colon cancer xenograft. Purified CEA-92 IgG was fragmented into F $(ab')_2$ and then labeled with $^{99m}Tc$ by transchelation method using glucarate as a chelator. Labeling efficiency, immunological reactivity and in vitro stability of $^{99m}Tc$ CEA-92 F $(ab')_2$ were measured and then injected intravenously into nude mice bearing human colon cancer (SNU-C4). Scintigrams were obtained at 24 hour after injection. Then nude mice were sacrificed and the radioactivity was measured Labeling efficiency of injected $^{99m}Tc$ CEA-92 F $(ab')_2$, immunoreative fraction and in vitro stability at 24 hour of injected $^{99m}Tc$ CEA-92 F $(ab')_2$ was 45.2%, 32.8% and 57.4%, respectively. At 24 hour after injection, % ID/g in kidney (46.77) showed high uptake, but %ID/g in tumor (1.65) was significantly higher than spleen (0.69), muscle (0.16), intestine (0.45), stomach (0.75), heart (0.48) and blood (0.45). There was no significant difference between tumor and liver (1.81). Tumor contrast as quantitated by tumor to blood ratio of $^{99m}Tc$ CEA-92 F $(ab')_2$ was increased significantly (p<0.005) until 24 hours (3.70), and there was no statistical differece from tumor to blood ratio of I-131 CEA-92 F $(ab')_2$. The scintigram demonstrated localization of radioactivity over transplanted tumor, but significant background radioactivity was also noted over kidney and abdomen. It is concluded that CEA-92 F $(ab')_2$ can be labeled with $^{99m}Tc$ by a direct transchelation method using $\beta-mercaptoethanol$ as a reducing agent and $^{99m}Tc$ labeled CEA-92 F $(ab')_2$ can be used for the scintigraphic localization of human colon cancer xenograft in nude mice model.

• Journal of Gifted/Talented Education
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• v.20 no.1
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• pp.107-130
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• 2010

The purpose of this study is to investigate the characteristics that indicate scientifically gifted students by analyzing the verbal interactions in developmental biology inquiry-experimental classes. The subjects were 20 first-grade middle school students who were participating in SNU Science Gifted Education Center. In these experimental classes which were developed based on the CPS Model, we conducted a total of four experimental sessions of small group discussions, and the students' verbal interactions were both taped and video recorded, and observed. From the transcriptions, the patterns of question-answer and the characteristics of scientifically gifted students were analyzed. In the case of question-answer patterns, thinking questions appeared 3~6 times more frequently than the standard information questions. Especially, the case of experimental class I showed 40% more thinking questions as well as standard information questions that the other 3 classes. Through the results of analysing verbal interactions, we were able to find more detailed aspects to creativity that were not identifiable in paper-pencil examinations, as well as affective characteristics such as task commitment and leadership. We believe our findings upon inquiry will be of substantial significance in substituting for the paper-pencil examination in distinguishing and selecting scientifically gifted students.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.149-159
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• 1999

Purpose: The purpose of this study was to evaluate cervical lymph node metastasis of oral squamous cell carcinoma patients by MRI film and neural network system. Materials and Methods: The oral squamous cell carcinoma patients(21 patients. 59 lymph nodes) who have visited SNU hospital and been taken by MRI. were included in this study. Neck dissection operations were done and all of the cervical lymph nodes were confirmed with biopsy. In MR images. each lymph node were evaluated by using 6 MR imaging criteria(size. roundness. heterogeneity. rim enhancement. central necrosis, grouping) respectively. Positive predictive value. negative predictive value. and accuracy of each MR imaging criteria were calculated. At neural network system. the layers of neural network system consisted of 10 input layer units. 10 hidden layer units and 1 output layer unit. 6 MR imaging criteria previously described and 4 MR imaging criteria (site I-node level II and submandibular area. site II-other node level. shape I-oval. shape II-bean) were included for input layer units. The training files were made of 39 lymph nodes(24 metastatic lymph nodes. 10 non-metastatic lymph nodes) and the testing files were made of other 20 lymph nodes(10 metastatic lymph nodes. 10 non-metastatic lymph nodes). The neural network system was trained with training files and the output level (metastatic index) of testing files were acquired. Diagnosis was decided according to 4 different standard metastatic index-68. 78. 88. 98 respectively and positive predictive values. negative predictive values and accuracy of each standard metastatic index were calculated. Results: In the diagnosis of using single MR imaging criteria. the rim enhancement criteria had highest positive predictive value (0.95) and the size criteria had highest negative predictive value (0.77). In the diagnosis of using single MR imaging criteria. the highest accurate criteria was heterogeneity (accuracy: 0.81) and the lowest one was central necrosis (accuracy: 0.59). In the diagnosis of using neural network systems. the highest accurate standard metastatic index was 78. and that time. the accuracy was 0.90. Neural network system was more accurate than any other single MR imaging criteria in evaluating cervical lymph node metastasis. Conclusion: Neural network system has been shown to be more useful than any other single MR imaging criteria. In future. Neural network system will be powerful aiding tool in evaluating cervical node metastasis.

• Nuclear Engineering and Technology
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• v.43 no.1
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• pp.25-44
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• 2011

KAERI has been operating an integral effect test facility, ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation), for accident simulations of advanced PWRs. Regarding integral effect tests, a database for major design basis accidents has been accumulated and a Domestic Standard Problem (DSP) exercise using the ATLAS has been proposed and successfully performed. The ATLAS DSP aims at the effective utilization of an integral effect database obtained from the ATLAS, the establishment of a cooperative framework in the domestic nuclear industry, better understanding of thermal hydraulic phenomena, and an investigation of the potential limitations of the existing best-estimate safety analysis codes. For the first ATLAS DSP exercise (DSP-01), integral effect test data for a 100% DVI line break accident of the APR1400 was selected by considering its technical importance and by incorporating comments from participants. Twelve domestic organizations joined in this DSP-01 exercise. Finally, ten of these organizations submitted their calculation results. This ATLAS DSP-01 exercise progressed as an open calculation; the integral effect test data was delivered to the participants prior to the code calculations. The MARS-KS was favored by most participants but the RELAP5/MOD3.3 code was also used by a few participants. This paper presents all the information of the DSP-01 exercise as well as the comparison results between the calculations and the test data. Lessons learned from the first DSP-01 are presented and recommendations for code users as well as for developers are suggested.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.150-159
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• 2011

This study was conducted to gather the basic data on the alpine leek (Allium victorialis) for the expand of consumption and the production of its manufactured goods. Amino acid content in alpine leek leaves and various physiological activities were examined. Seventeen component amino acids and 38 free amino acids from alpine leek leaves were analyzed, and the total contents were 2,693.28 mg/100g for component amino acids and 535.39 mg/100g for free amino acids. Total phenolic compounds in the leaves of alpine leek showed the highest level from the methanol extract (37.7 mg/l), and followed by ethanol extract (31.9 mg/l) and hot water extract (25.4 mg/l). Total flavonoid contents in 1,000 mg/l extract was the highest in the methanol extract (22.2 mg/l). DPPH radical scavenging activity at 1,000 mg/l extract was high in the order of ethanol extract (51.6%), methanol extract (47.3%) and hot water extract (37.2%). nitrite radical scavenging activity Methanol extract from Allium victorialis leaves was the highest nitrite radical scavenging activity (79.5%). Hyperplasia suppression of lung cancer cells (Calu-6) and gastric cancer cells (SNU-601) by the methanol extract from the bulb of alpine leek were 99.9% in the extracting concentration of over 200 mg/l. No significant difference in antimicrobial activity among the 3 different solvents and extract concentrations was observed, and the inhibition zones against the gram-positive and negative microorganisms were ranged from 8.23 to 10.15 mm. It was concluded that physiological activities in a human body could be improved by the intake of alpine leek as a pharmaceutical material, and that it would be useful for the prevention of health risk such as lung and gastric cancers.

• Publications of The Korean Astronomical Society
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• v.22 no.4
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• pp.133-140
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• 2007

We have determined the disk size of Be stars by using $H{\alpha}$ emission. We observed spectra of Be stars with telescope in SNU, equipped with SB SGS (Santa Babara Self Guided Spectrograph) and CCD ST-8. The size of disk of Be stars was estimated with the Be star model of Grundstrom & Gies (2006). This study suggests that the medium resolution spectra taken with small telescope equipped with commercial spectrograph are useful to estimate the approximate size of the $H{\alpha}$ emitting disk around Be stars.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.373-383
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• 2018

Background: Several epidemiologic studies have suggested that the urine sodium excretion (USE) can be estimated in lieu of performing 24-hour urine collection. However, this method has not been verified in patients with chronic kidney disease (CKD) or in an interventional study. The purpose of this study was to evaluate the usefulness of estimating USE in a prospective low-salt diet education cohort (ESPECIAL). Methods: A new formula was developed on the basis of morning fasting urine samples from 228 CKD patients in the ESPECIAL cohort. This formula was compared to the previous four formulas in the prediction of 24-hour USE after treatment with olmesartan and low-salt diet education. Results: Most previously reported formulas had low predictability of the measured USE based on the ESPECIAL cohort. Only the Tanaka formula showed a small but significant bias (9.8 mEq/day, P < 0.05) with a low correlation (r = 0.34). In contrast, a new formula showed improved bias (-0.1 mEq/day) and correlation (r = 0.569) at baseline. This formula demonstrated no significant bias (-1.2 mEq/day) with the same correlation (r = 0.571) after 8 weeks of treatment with olmesartan. Intensive low-salt diet education elicited a significant decrease in the measured USE. However, none of the formulas predicted this change in the measured urine sodium after diet adjustment. Conclusion: We developed a more reliable formula for estimating the USE in CKD patients. Although estimating USE is applicable in an interventional study, it may be unsuitable for estimating the change of individual sodium intake in a low-salt intervention study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.534-538
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• 1997

Some physiological characteristics and cultivar differences of winter barley to salt stress were studied during seedling stage. Salt stress was caused by adding NaCl solution to the pot culture soil. Measurements of the responses to salt stress and of the responses after relief from stress were done in terms of leaf water potential, chlorophyll and free proline contents, seedling height and seedling dry weight, and survival rate of leaves. Under salt stress ($\Psi_{\pi}$ =-20bar) seedling height and seedling weight were decreased by 2~22% and by 25~39% respectively, showing some differences among cultivars. Chlorophyll contents was decreased by 33~49%, and free proline content was remarkably increased from control 0.2~0.3mg to salt stress 9.6~14.7mg. The leaf water potential of seedling grown under salt stress with NaCl solution($\Psi_{\pi}$ =-10 or -20bar) was decreased from control -3.3bar to salt stress -9.0bar or -16.2bar respectively but there were no large differences among cultivars with time after relief from salt stress. Leaf survival rate was high in order of Baegdong, Milyang12, Olbori, Durubori and Hyangmaeg, and decrease rate of seedling dry weight was low in the order of Baegdong, Olbori, Hyangmaeg, Milyang12, Durubori. The increase in free proline contents was high in the order of Milyang12, Hyangmaeg, Baegdong, Durubori and Olbori.