• Journal of Korean Society of Water and Wastewater
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• v.26 no.1
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• pp.47-54
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• 2012

This study analyzed influence factors and the correlation among pollutants which affect occurrence of leaked pollution based on the long-term runoff flow and water quality investigation results to understand the characteristics of highway rainfall runoff pollution load. According to the result of correlation analysis on TSS (Total Suspended Solid) concentration, anteceded dry days, rainfall intensity, traffic volume and etc. as major influence factors of highway rainfall runoff pollution loads, the correlations were weak or scarce in most items. These results might be attributed that runoff pollutant concentration changes vary severely on changes of rainfall intensity and rainfall duration within rainfall and it is affected by disturbances of vehicles and street cleaning and etc. as characteristics of the highway. While Cu, Fe and Zn which are discharged with high concentrations out of heavy metals showed high correlation with particulate matter, organic matter(COD), nutrient(TN, TP), Ni and Pb showed relatively low correlation in a correlation evaluation by pollutant. Significant correlation with traffic volumes was not shown and TSS concentration even decreased in accordance with increase of the traffic volume. In the comparison with precedent studies, it was considered necessary additional analysis of the effects of rainfall section analysis, road type, disturbances of surface contaminants by vehicles, rainfall and climate conditions, surrounding terrains etc.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.584-588
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• 1997

Lots of forginfs used in automobile and aerospce industries are made in hot or cold working conditions, depending on the size and shape of a product. Usually the die design for new items has been first made on the basis of experiences and many know-hows accumulated in the company and then slightly modified through trial and error method to get the desired forgings without defects. Most of drawings at the die design stage have been manually drawn, butrecently some of forging companies have begun to apply a computer-aided drafting technique to the die design for reducing drafting time as well as repeatedly utilizing standardized parts form registerd data base. In this paper the automated die design technique for forward extrusion of axisymmetric forgings is developed by using AutoLISP language. For this study the representative die system is determined form the investigation of several types of forging dies being currently employed in the metal forming field and the design rules for cold extrusion die are summarized and programmed on a personal computer. A few design examples of forward extrusion die are given and discusses.

• Journal of Welding and Joining
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• v.9 no.3
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• pp.41-51
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• 1991

The thermomechanical coupling phenomena in the resistance welding process is complicated due to interactions of mechanical, thermal and electrical factors. Although experimental investigations of resistance spot welding have been carried out, but there are a few by computer simulation. so the purpose of this research is to decrease the time and cost much required in experimental investigation by carrying out the analysis of the resistance spot welding process through computer simulation based on the finite element method. The tool used in the computer simulation is the commercial ANSYS program package. A two dimensional axisymetric model is used to simulate the resistance spot welding for two stainless steel sheets of equal thickness and parametric study is carried out for variable welding current, workpieces of unequal thickness and dissimilar materials. The results from the computer simulation are in good agreement with the experimental one. Through these results, such items as stress distribution, temperature profiles, thermal expansion and weld nugget formation are predicted. Reliability and applicability of finite element models have been demonstrated to simulate and to analyze the resistance spot welding process.

• Journal of Korean Home Economics Education Association
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• v.15 no.1
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• pp.57-68
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• 2003

The purpose of this study was to research high school students’ practical awareness about the contents(classify them into four units. choice and dressing of clothes. textile and management of clothes. design and sewing of clothes. knitting and embroidery) clothing and textiles education in their real life. This is the investigation of which 576 high school students located in Choongchungnam$.$bukdo. Junrabukdo, Daeseon. In this statistical analysis. SPSS 10.0 for Windows Program was utilized to calculate percentage. mean and standard deviation. Also. these materials were verified by t-test. One-way Anova . Pearson’s correlation coefficient. The main results of obtained this study are as follows High school students’ practical awareness about the contents of clothing and textiles education in their real life appears to be low(only 9 items were over median point of 3.0). There was a significant difference in Practical awareness of contents of clothing and textiles education according to demographic variables. and correlation of variables differed significantly. These results should be provide fundamental information for improving students’ practical practice in their real life Since this study has touched only limited research on the topic of clothing and textiles education. it is essential that further research covering a wider array of themes be done in the future.

• 한국전기화학회:학술대회논문집
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• 1998.12a
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• pp.153-166
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• 1998

Lithium ion Batteries commercially available since the early nineties in Japan are going to be more and more important for portable electronic devices and even EV applications. Today several companies around the world are working hard to join to market for Lithium secondary batteries. Based on the growing interest for commercial use of batteries also the materials have to be reviewed in order to meet large scale production needs. The requirements especially for electrolytes for lithium batteries are extremely high. The solvents and the lithium salts should be of highest purity. So the supply of these chemicals including packaging, transportation and storage but also the handling in production are critical items in this field. Frolic impurities are very critical for LiPF6 based electrolytes. The influence of water is tremendous. But also the other protic impurities like alcoholes are playing an Important role for the electrolyte quality. The reaction of these species with LiPF6 leads to formation of HF which further reacts with cathode materials (spinel) and anode. To understand the role of the protic impurities more clearly the electrolyte was doped with such compounds and was analyzed for protic impurities and HF. These results which directly show the relation between impurities and quality will be presented and discussed. In addition several investigations on different packaging materials as well as methods to analyze and handle the sensititive material will be addressed. These questions which are only partly discussed in literature so far and never been investigated systematically cover some of the key parameters for understanding of the battery chemicals. This investigation and understanding however is of major importance for scientist and engineers in the field of Lithium ion and Lithium polymer batteries.

• Journal of the Economic Geographical Society of Korea
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• v.5 no.2
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• pp.157-174
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• 2002

This study aims to examine the structure and meaning of the perception of rural amenity which rural and urban residents have. Many Lickert scaled questions measure how much important the respondents think about the various items related to rural amenity respectively. It reveals that there is not meaningful difference in the relative importance among three upper dimensions composing the construct of rural amenity, historic-cultural dimension, natural environmental dimension and living condition dimension. This means that our respondents are not willing to pursue historic-cultural aspects and natural environmental aspects at the risk of living condition being able to enjoy comfortable and affluent opportunities. And also, this results reveals that people might have a quite different perception compared with academic discourse putting much weight on historic-cultural dimension and natural environmental dimension.

• Journal of Preventive Medicine and Public Health
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• v.47 no.3
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• pp.177-181
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• 2014

Objectives: A salmonellosis outbreak occurred within a community of Gyeongju residents who ingested catered food from a wedding in June 2009. We aimed to epidemiologically investigate the probable vehicle of the infection. Methods: We conducted a retrospective cohort study on 34 local residents who ingested the wedding food. Results: Among the 34 residents, 31 (91.2%) reported symptoms of infection after eating the food. Among all of the wedding foods, pan-fried foods were highly associated with the diarrheal attack rate. On bacteriological examination, Salmonella species were detected in the pan-fried foods among the leftover foods and in 17 of the 31 stool specimens from the cases. There were five different types of pan-fried foods, but the onset of symptoms was independent of the ingredients used. We found that the pan-fried food was prepared at a food store in Seoul and that eggs were a common ingredient. Conclusions: The major cause of the salmonellosis in this population was presumed to be the pan-fried food prepared with contaminated eggs. These food items might have been partially undercooked because of their irregular shape, which allowed the Salmonella species to survive and multiply before ingestion.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.971-978
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• 2014

Investigation of the quality characteristics of Takju brewing mashes prepared with several different yeasts was carried out during the 42-day brewing process, including examination of titratable acidity, amino acid content, sugar contents, alcohol contents, pH, reducing sugar, yeast population, lactic acid bacteria, and sensory evaluation. Fermivin yielded the highest titratable acidity, while la parisienne had the lowest. Fermivin also had the highest value of amino acid content (14.33%), while other yeasts shows period tended to increase over exclude Instaferm and Song chun. The amount of sugars in instaferm ($11.33^{\circ}Bx$) and instaferm red ($10.53^{\circ}Bx$) were higher than those in La parisienne red and Song chun ($9.57^{\circ}Bx$). The alcohol contents of instaferm was the highest value (15.20%) while the alchol content of the other yeasts tended to increase the fementation period. Fermivin had the highest pH at $12^{th}$ day among the yeasts(4.02), Instaferm red had the lowest pH among the yeasts (3.87) while safbrew wb-06 had the highest reducing sugar content(117.60 mg/mL). Instaferm obtained the highest preference in the sensory evaluation for all items.

• Korean Journal of Child Studies
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• v.32 no.2
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• pp.35-52
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• 2011

The purpose of this study was to evaluate the validity and reliability of the Penn Interactive Peer Play Scale (PIPPS) for Korean young children, with a special confirmative factor analysis. The participants were composed of 435 5-to 6-year-old children and their parents, and 42 teachers. The instruments included the 32-item exploratory PIPPS (Choi & Shin, 2008), the Preschool Behavior Questionnaire (PBQ; Park, 1992), and the PIPPS on parental reporting. The PIPPS was confirmed, and supported the following constructs resulting in the investigation of 3 factors, 'play disruption', 'play interaction', and 'play disconnection', along with 30 items similar to the PIPPS (2008). Inter-correlations between the sub-factors of PIPPS with those of criterion measures were validated by ratings from the PBQ and the parent version of the PIPPS. The reliability coefficients of the sub-factors of the PIPPS ranged from .85 to .92. In conclusion, 3 factor structure of the PIPPS was appropriate to represent the interactive peer play of Korean young children.

• Journal of Korean Elementary Science Education
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• v.30 no.4
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• pp.514-523
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• 2011

The purpose of this study was to investigation the elementary school teachers' perception in STEAM(Science, Technology, Engineering, Arts, Mathematics) Education. For this study, 93 elementary school teachers who have taught mathematics/science in gifted class were selected and a fifteen items questionnaire designed to elicit teachers' perception of steam education was to administered to them. The major findings are as follows: First, the ratio of teachers who understood a steam education exactly is very low. But teachers have positive thoughts about the need of steam education. Second, teachers thought that steam education has a good effect on elementary education. Third, teachers thought that steam education will be an alternative teaching and learning method. Fourth, teachers have negative thoughts to participate in class work related on steam education. To improve negative attitudes on steam education, incentives for teachers seems to be required. In order to spread steam education among the elementary school teachers successfully, the expansion of school facilities, administrators and staff in mind, improving financial support, strengthening education through the development of content and teaching strategies were analyzed as a challenge.