• 한국과학교육학회지
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• 제6권2호
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• pp.15-33
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• 1986

The main purpose of this study is to analyze the fourth and sixth grade in the elemental)' science contents using piagetian thinking patterns. An analysis of the elementary Science contents used the systems of Han Jong-Ha(1977), Lee Won-Shic and Lee Sang-On(1979). They analyzed the science contents based on Piagets' cognitive developmental stages. According to the results of this study, science contents consist of more difficult concepts those of children's thinking level. In other words, 6.4-19.3 percent to 23.5-25.0 percent in the fourth and sixth grade of the science contents are consisted with abstract level concepts that formal operational children can perform. But each grade, 99.2-95.3 percent of children have a difficulty in understanding such a abstract level concepts. They are in the concrete operation thinking level. Therefore, we say that children have difficulty in understanding of science contents and may lose interest in the contents.

• 플랜트 저널
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• 제8권1호
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• pp.73-80
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• 2012

The structure and combustion characteristics, and the economic feasibility of the circulating fluidized bed combustion(CFBC) boiler using low grade coal were introduced. The economic feasibility is evaluated by comparing a 500 MW CFBC boiler power plant using low grade coal and a pulverized combustion boiler power plant with high grade coal. As the result of the evaluation, the pulverized coal combustion boiler power plant has an internal rate of return of 12.95%, 1,395.9 billion Korean won of net present value, and 6.26 years of payback period. On the other hand, CFBC boiler power plant has an internal rate of return of 13.54%, 1,704.3 billion Korean won of net present value, and 6.02 years payback period. Therefore, the CFBC boiler power plant has better feasibility in all aspects, as 0.59% higher of internal rate of return, 308.4 billion Korean won of higher net present value and 0.24 year of shorter payback period.

• 한국학교보건학회지
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• 제30권2호
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• pp.154-163
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• 2017

Purpose: This study aimed to understand the current situation of Korean adolescents' sexual experience and its characteristics by school level, gender, and related factors to their sexual experience. This could be the basic evidence for the development of various sex education programs for the youth. Methods: This study used the 11th online survey data on youth health behavior (2015) and all 68,043 students who participated in the study were included for the analysis. The binominal logistic regression model was used to identify the characteristics and relevant factors of sexual intercourse experience. Analysis was performed by complex sample design using SPSS/WIN 18.0. The statistical significance was defined as p<.05 with a two-sided test. Results: The factors related to sexual experience of adolescents included grade, sadness and hopelessness, smoking, Internet addiction, and sex education in school, for middle school boys. For middle school girls, grade, residence area, sadness and hopelessness, smoking, drinking, and sex education in school were related. For high school boys, the factors were grade, living with parents, economic situation, sadness and hopelessness, smoking, drinking, and Internet addiction. For high school girls, grade, sadness and hopelessness, smoking, and drinking were found to be related factors. Conclusion: The results of this study suggest that a practical program considering adolescents' level and characteristics should be developed and applied.

• 한국학교보건학회지
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• 제16권2호
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• pp.85-95
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• 2003

This paper surveys and researches primary school students' situation of their school life. The purpose of this paper is to propose the basic information of the accident prevention teaching and the safety management in order to avoid accidents to occur beforehand. We selected m primary students out of the six primary schools in Taebaek City at which the nursing students of Kangwon Tourism College practiced school health. We used SPSS Win for analyzing data. We carne up with the general characteristics and percentage using frequency analysis, mean and standard deviation of each item, the mean difference using T-Test, and the different factors using one-way analysis. The results are as follows: 1. The 6th grade students don't practice safety procedures than the 5th grade students during outside the school. The older the student is, the less it practices safety procedures. 2. Boys practice safety procedures better than the girls during inside and outside the school. 3. Hot -tempered students don't practice safety procedures properly. 4. Most of the students who often use the health room of the school have high scores in safety procedures test and as a result, these students practice safety procedures thoroughly. 5. The grade of safety living activity is the highest during gymnastic class. Next is when the students use the stairs when they are going up and clown. Then, the use of science room In the playground is the lowest grade of safety for living activity.

• 대한골관절종양학회지
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• 제1권2호
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• pp.181-188
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• 1995

Malignant tumor of the pelvic bone has nonspecific symptom and it is not easily detected by physical examination or by radiologic study in early stage, because of its anatomical characteristics. Associated with their variety of disease entity, the treatment of malignant pelvic bone tumor is a problematic point. We have analysed 36 cases of malignant pelvic bone tumors diagnosed at the Severance hospital from 1968 to 1993 to provide a reference for diagnosis and treatment of the malignant pelvic bone tumors. We found that the chondrosarcoma(27.8%) and the osteogenic sarcoma(27.8%) were the most common type of pelvic bone malignancy, and then, in the order of incidence, there were Ewing's sarcoma(16.7%), malignant fibrous histiocytoma(11.1%). There were differences of the age distribution among each diseases and the average age was Ewing's sarcoma 20.5, osteogenic sarcoma 27.2, chondrosarcoma 40.0, malignant fibrous histiocytoma 64.8, respectively. Three of the 5 patients with low grade tumors survived(60%), whereas 3 of the 17 patients with high grade tumors survived(18%). The survival rate of the low grade malignant group was 60%, the high grade was 18%.

• 한국안전학회지
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• 제29권6호
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• pp.87-93
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• 2014

In this study, the reinforced concrete rahmen bridge damaged by the chloride attack was investigated. According to the investigation, the degraded concretes on cantilever kerb and end part were intensively observed. Thus, the chloride content test and half-cell method were performed to evaluate the degraded parts. As a result, the contents of chloride on degraded parts were C and D grade. On the other hand, the half-cell potential values of rebar in degraded concrete were measured with the minor corrosion. This rebar corrosion is expected to progressing. Chloride content D grade is due to expansion pressure by corrosion of rebar and freeze-thaw by permeate water, could see progresses rapidly degradation. In order to prevent chloride attack to concrete deck caused by deicing salts, corresponding to the chloride critical concentration must maintain grade b or at least grade c. Chloride condition evaluation standard apply to evaluation of marine structure chloride attack with chloride attack by deicing salts.

• Ocean Science Journal
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• 제41권3호
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• pp.149-161
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• 2006

The aims of this study are 1) to construct a database using geostatistics and Geographic Information System (GIS), and 2) to derive the spatial relationships between manganese nodule abundance and other geological factors such as metal grade, slope, water depth, topography, and acoustic characteristics of the sub-bottom. Using GIS, it is possible to analyze a large amount of data efficiently, and to maximize the practical application, to increase specialization, and to enhance the accuracy of the analyses. The greater the copper and nickel grade, the higher the rating. The distribution pattern of nickel grade is similar to that of copper grade. The slopes are generally less than $3^{\circ}$ except for seamounts and cliff areas. The rating shows no correlation with slope. The rating is highest for slopes between 2.5 and $3.5^{\circ}$ in block N1 and between 4.0 and $4.5^{\circ}$ in block N3. The topography is classified into five groups: seamount, hill crest, hill slant, hill base or plain, and seafloor basin or valley. The rating proves lowest for seamount and hill crest. Our results show that the rating increases with the water depth in the study area. Nodule abundance dose not show any significant relationship with the thickness of the upper transparent layer in the study area.

• 한국자동차공학회논문집
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• 제17권4호
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• pp.48-54
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• 2009

The demand for formable high-strength steel (HSS) sheets has recently increased to reduce the weight of automotive bodies. The 340MPa (Tensile Strength) grade steel sheets are widely used for body inner and outer panels. Especially, super formable 340MPa grade steel sheets with high r-value have an excellent deep drawability compared with the other 340MPa grade steel sheets. It is very available for a part such as rear floor, center floor and dash panels used conventional mild steels up to now. We developed a super formable HSS by optimization of chemical composition, texture control and heat treatment control. It has good mechanical properties with excellent formability (tensile strength: 343MPa, elongation: 41.1% and $\bar{r}=2.1$).

• 한국간호교육학회지
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• 제19권4호
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• pp.648-655
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• 2013

Purpose: This study was conducted to investigate the level of interpersonal attachment styles and love styles and to identify the differences of love styles according to interpersonal attachment styles among nursing students. Methods: Data were collected from 510 nursing students using a self-report questionnaire and analyzed by frequencies, Fisher's exact test, t-test, and ANOVA using the SPSS program. Results: In terms of interpersonal attachment styles, secure style was the most prevalent, and fearful style was the second highest in nursing students. There were significant differences in interpersonal attachment styles between upper and lower level nursing students, indicating the highest rate of secure style in the lower grade and the highest rate of fearful style in the upper grade. In love styles, the mean scores for eros and pragma style in nursing students were significantly higher in the upper grade than the lower grade. Love styles according to interpersonal attachment styles showed a significant difference for eros style. Conclusion: Our results might help nursing educators increase their understanding of interpersonal attachment styles and love styles in nursing students and counsel nursing students in interpersonal and romantic relationships. In addition, educational programs addressing interpersonal attachment styles should be developed and applied to nursing students.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.215-219
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• 2001

Impurities removal from waste carbon black was carried out to produce high-grade carbon black. A lot of hydrophilic carbon black is produced as a byproduct of the hydrogen production process by flame decomposition of water. Due to its impurity content such as sulphur, iron, ash and etc., it can only be used as low-grade carbon or burnt out. High-grade hydrophilic carbon black is 3-5 times more expensive than oil-based carbon black because of its process difficulties and requires pollutant treatment. Hydrophilic carbon is normally used far conductive materials for batteries, pigment for plastics, electric wire covering, additives for rubber, etc.. In these applications, hydrophilic carbon must maintain its high purity. In this study magnetic separation, froth flotation and ultrasonic treatment were employed to remove impurities from the low-grade hydrophilic carbon black. As results, the ash, iron and sulphur content of product decreased to less than 0.01wt.%, 0.0lwt.% and 0.3wt.% respectively, and the surface area of product was about 930 $m^2$/g.