• Korean Journal of Child Studies
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• v.27 no.5
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• pp.49-65
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• 2006

This attitudes scale for prediction of mathematics achievement by elementary school students was developed from 50 initial items from the literature rated for content validity by 30 experts. The ratings rendered 31 revised items used for exploratory factor analysis and reliability tests. The 31 items were administered to 183 elementary students in 4th, 5th, and 6th grades, yielding 4 factors : enjoyment, confidence, value, and motivation with high inter-items consistency. To confirm appropriateness of the constructed model and to test its predictability in mathematics achievements, confirmative factor analysis and discriminant analysis were performed on 693 cases. Results showed that the attitude scale model of 4 factors can be recommended for use in the measurement of elementary school students' attitudes toward mathematics.

• Korean Journal of Child Studies
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• v.14 no.1
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• pp.91-107
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• 1993

The purpose of this study was to examine the social and cognitive competence of the only children in comparison with children with siblings. The sample consisted of 360 children from kindergartens, elementary schools(2nd and 5th grades), middle schools and high schools in Seoul. Data were gathered through questionnaires on social and cognitive competencies. The results were as follows: (1) The differences in social and cognitive competence between only children and sibling children varied by age of the child. (2) There were no significant differences according by sex in social competence and cognitive competence among both only children and sibling children. (3) The voluntariness of fertility outcomes was not related either to the social or cognitive competence of only children for each age group.

• The Mathematical Education
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• v.44 no.4 s.111
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• pp.509-524
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• 2005

The purpose of this study is to investigate the current state of the contents of the mathematics education that are implemented for 3-10 grade students in Korea. To satisfy the purpose of the study, we conducted a nationwide questionnaire to get opinions from students on the relevance of the mathematics curriculum. 4,158 elementary school students, 4,571 middle school students, and 1,653 high school students participated in this survey. Many students feel that the quantity is relevant, so the requirement of reduction in quantity is a little. Also secondary students feel that mathematics is difficult and this condition becomes more serious in proportion as grade. Finally we noticed the difference between sexes, grades, and tracks of studying in every question.

• Korean journal of food and cookery science
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• v.18 no.6
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• pp.579-585
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• 2002

A survey on the school foodservice was conducted from 693 middle school students to examine their degree of satisfaction on foodservice with the object to enhance the quality of school foodservice in Gwangiu and Chonnam area. The degree of satisfaction with school foodservice ranked high in taste, temperature and service categories. There were notable differences in the satisfaction level by the gender of the students. Male students ranked higher than female students in taste, temperature and the sanitary condition of food containers. According to grades, first grade students ranked the highest in satisfaction of food selection, temperature, services and cafeteria. Regarding the amount of left-overs, soup and pot-stew were the greatest followed by side dishes. Reasons for leftover food were listed as being tasteless, having no appetite, or large serving size. The items of priorities on school foodservice were revealed as sanitary conditions, taste and variety in menu selection by the students.

• Parasites, Hosts and Diseases
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• v.22 no.1
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• pp.141-143
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• 1984

The head louse infestation had been no problem since 1960s in Korea. However, the present study revealed high infestation rate among the primary school children in Seosan-gun, Chungnam Province in July 1983. The cases of louse positive were determined by identifying the adult worms and/or their llits on scalp and hairs. The overall louse positive rate among 615 children examined was 73.5%. The rate was higher in girls (78.8%) than in boys (67.6%) and was highest in 3rd-4th school grades. It was observed that the more the number of family members the higher the infestation rate of children. The positive children were treated with 20% benzyl benzoate solution after the teat for louscidal effect in petri dish. However, establishment of intensive control measure is needed to prevent further infestation.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2007.05a
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• pp.57-82
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• 2007

Rebuilding an existing paper machine is often a very profitable way for papermakers to increase the cash flow created by an older paper machine. In Metso Paper we have placed particular emphasis in recent years on developing concepts and products specifically for rebuild needs. The outcome of this work can now be seen as a wide selection of products offering quite possibly the best coverage of all time of specific improvement targets. Different needs can be addressed through truly different solutions. Selecting the best-fit alternatives will offer great upgrade options for all paper machines and paper grades. Metso Paper's long experience with high-speed paper machines has been put to good use to create more cost-effective small and mid-sized solutions with the reliability and quality of bigger and faster paper machines. This paper has discussed some of the most interesting and latest configurations available today for paper machine rebuilds.

• Corrosion Science and Technology
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• v.14 no.6
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• pp.253-260
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• 2015

The pitting behaviours of 304L and 316L stainless steels were investigated at $3^{\circ}C$ to $90^{\circ}C$ in 1 M solutions of NaCl, NaBr and NaI by potentiodynamic polarization. The temperature dependences of the pitting potential varied according to the anion, being near linear in bromide but exponential in chloride. As a result, at low temperatures grades 304L and 316L steel are most susceptible to pitting by bromide ions, while at high temperatures both stainless steels were more susceptible to pitting by small chloride anions than the larger bromide and iodide. Thus, increasing temperature appears to favour attack by smaller anions. This paper will attempt to rationalise both of the above findings in terms of the point defect model. Initial findings are that qualitatively this approach can be reasonably successful, but not at the quantitative level, possibly due to insufficient data on the mechanical properties of thin passive films.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.58-63
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• 1999

Almost all concrete structures have many inevitable cracks for various reasons such as drying shrinkage, heat liberation of cement, fatigues or repeating loads and movements. Conventionally, they are repaired with epoxy materials. The Epoxy resins used by repair materials are different from properties of the base concrete materials such as thermal and mechanical properties - thermal expansion coefficients, bending strength. And the epoxy resin cannot release the water inside the concrete structure and cause corrosion of the steel bars. In this study, before the experiment got launched, we had analyzed cement and slag. Then We blended the two grades of ultra fine cement using high blaine cement and slag. And the cement slurry was produced by water and suprplasticizer to each blended ultra fine cement in various conditions. The slurry produced by each conditions was evaluated with flow properties such as viscosity, dropping time, segregation and observation of dry surface after injection.

• Journal of Families and Better Life
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• v.27 no.5
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• pp.115-122
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• 2009

This study investigated the mediating and moderating effects of teacher preference on the relationship between behavior problems and peer victimization. The subjects were 520 children in the fifth and sixth grades. Children completed peer nominations that assessed peer victimization. Teachers rated children's internalizing, externalizing problems and teacher preference. The full mediating effect of teacher preference was found in externalizing problems and the partial mediating effect was found in internalizing problems. Moreover, the moderating effect of teacher preference was found only in internalizing problems, which suggests that high teacher preference protects internalizing problems from peer victimization.

• Journal of the Korean Ceramic Society
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• v.19 no.1
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• pp.35-43
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• 1982

It was found that the burnability of raw mix and characteristics of clinker was affected by the difference in grades of limestones. The thermal decomposition temperature of raw mix which used low grade limestone was lower than that of high grade, and the fast formation of $C_2S$ was due to the rich content of calcite and quartz over critical grain size, which caused the bad effects in the burnability, but $C_3S$ was formed slowly. The structure of clinker had many pores, and the growth of clinker minerals was inferior.