• School Mathematics
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• v.13 no.4
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• pp.675-696
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• 2011

This study was designed to understand PCK to improve professionalism of teachers and derive implications about proper teachings methods. For achieving these research purposes, different PCK and teaching methods in class of three teachers were compared and analyzed targeting arithmetic operation unit of fraction. For this study, criteria of PCK analysis of teachers was set, PCK questionnaires were produced and distributed, teachers had interviews, PCK of teachers were analyzed, two times fraction class was observed and analyzed, and PCK of teachers and their classes were compared. Followings are results to analyze PCK of teachers about fraction. In relation to PCK of three teachers, first of all, A teacher accurately understood concepts of fraction and learners' errors that may occur when they study fraction. Also, he(she) proposed concrete teaching strategies for fraction based on manipulated materials. B teacher also understood concepts of fraction and learners' errors accurately too. On the other hand, C teacher laid stress on knowledge to stress principles and taught that they are bases for every class. These results mean that self-training and inservice- training should be efficiently upgraded to improve PCK of teachers.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.8 no.3
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• pp.357-365
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• 2001

Purpose: The purpose of this study was to identify the death orientation of college student nurses and to evaluate the effectiveness in death orientation of a class on 'hospice care'. this was done by investigating the difference between the death orientation before and after the class. Method: The instrument used in this Investigation was the death orientation scale developed by Thorson and Powell (1988). The subjects of the study were the 47 college student nurses in a 'hospice care' class. The research was carried out between March 2, 2001, when the class began, and June 21, 2001 when the class ended The collected data were examined using arithmetic mean, percentage, t-test, ANOVA. Result: The results of the study are as follows : 1. The average death orientation score of the subjects before the class was 2.80. 2. There were a significant difference in the death orientation scores before and after the class (p<0.001). Before the class, 'hospice care', the students had an average score of 2,80. Their average score decreased to 2.55 after the class. Of 25 death orientation items on the scale, 14 items decreased significantly after the class as compared to before the class. 3. According to personal attributes (religion. the existence of religion, the experience of a death in recently) of subjects, there were no significant statistical differences in death orientation (p>0.05). Conclusion: This study showed that a class on hospice care was effective in changing the death orientation of student nurses.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.93-103
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• 2008

This research is designed for a consumer, not a supplier when it was designed. And the purpose is to present the reference data which is in order to improve the curriculum by analyzing the present subject of the curriculum. The research collected the curriculum for Dental Technology from a total of 20 schools --3-year colleges and 4-year colleges-- all in Korea. And we analyzed the average credits of subjects from students. As a result of this analysis, we get the conclusion below: 1. In a distribution which students answered about each subjects; Dental esthetic, Dental morphology I II, Dental morphology practice I II, and Seminar don't have many credits and mostly have a converged tendency in high points, according to the arithmetic mean of the major basis subjects. 2. In an analysis of the correlation which is based on the distinction of sex; Dental ceramics practice III, Medical terminology, Seminar, and The major basis subjects have a meaningful difference. (${\rho}$ < 0.05) 3. In an analysis of the correlation which is based on an age; The major basis subjects, and the application subjects have meaningful difference. (${\rho}$ < 0.05) 4. In a correlation coefficient between subjects; The correlation coefficient of the major application subjects is higher than the major basis subjects. According to the student ? t, we found that the level of significance is ${\rho}$ < 0.001, which is meaningful. We feel that Department of Dental Technology also highly need to design, and conduct focusing on a consumer who is working at the society, not a supplier. And we need to increase or decrease credits which have a meaningful difference.

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.49-64
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• 2007

This research collected the curriculum for Dental Technology from a total of 20 schools -3-year colleges and 4-year colleges- all in Korea. And we analyzed the average credits of subjects from students. As a result of this analysis, we get the conclusion below: 1. In a distribution which students answered about each subjects; Seminar, Dental morphology I II, Dental morphology practice I II, and Dental devices & instruments don't have many credits and mostly have a converged tendency in high points, according to the arithmetic mean of the major basis subjects. 2. In an analysis of the correlation which is based on the distinction of sex: Complete denture prosthodontics I II III, Dental orthodontics I II, Dental orthodontics practice I II, and Dental orthodontics & practice III have a meaningful difference. ($\rho$< 0.05 ) 3. In an analysis of the correlation which is based on an age The major basis subjects -Introduction to dental technology, Dental esthetic, and Dental casting procedure-, and the major application subjects -Crown and bridge prosthodontics practice, Complete denture prosthodontics, Dental orthodontics, Dental orthodontics practice, and Operative dentistry laboratory technology- have meaningful difference. ($\rho$< 0.05 ) 4. In a correlation coefficient between subjects; The correlation coefficient of the major application subjects is higher than the major basis subjects. According to the student - t, we found that the level of significance is $\rho$< 0.001, which is meaningful. We feel the lack of a limitation which we didn't survey all students who are major in Department of Dental Technology. And we also feel that we'd better to consider not only students who being in college but also graduated students.

• Journal of Families and Better Life
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• v.3 no.1
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• pp.94-106
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• 1985

The purpose of this study is to apprehend college women's views on marriage in order to systematize the view theoretically, and to investigate the relationship between the self-actualization and their marriage perspective. Futhermore, it is my hope to provide some basic materials for making an desirable view on marriage. The measuring tools used for preparing this study are self-actualization test, which were designed originally by Shostrom and standardized to be suitable for Korean society by Kim Jae Ean and Lee Kwang Ja and a questionnaire about one's view on marriage. Statistical methods such as frequency, percentile, arithmetic mean, analysis of variances(X2 and F values)were used for data analysis. The results of this study are as follows; 1) It is revealed that more than half(59.7%) of the college women achieve normal or above normal degree of self-actualization. 2)It is revealed that most college women's attitude toward matrimony is positive and they have a large acquaintance with the opposite sex. Especially, they are eager to became employed after entering into matrimony. 3) It is revealed that the more satisfaction a college woman's mother feels about her own matrimony, the more positive attitude her daughter has toward marriage. some college women who do not want to have a child have a positive attitude toward divorce. This means that their matrimony depends upon their view of marriage. 4) It is revealed that the more self-actualization college women feel, the more negative attitude they have toward selecting their husband. 5)It is revealed that the less self-actualization college women feel, the more negative attitude they have toward having a large acquaintance with the opposite sex and they have a dependent attitude toward living with their parents 6) It is revealed that most college women want their husband to have higher academic career than hers regardless of her own self-actualization degree and they want have a job after entering into matrimony. It seems to be dispassionate reflection of contemporary thought.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E1
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• pp.1-9
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• 2007

In Korea, there is only a limited amount of information currently available on the levels of airborne bacteria and fungi of cattle sheds, although certain portions of people are potentially exposed to these bioaerosols in cattle sheds. Accordingly, the current study measured them inside cattle sheds, inside and outside farmers' houses near the sheds, and/or inside residential houses far away from the sheds during winter, 2004 and summer, 2005. The airborne bacteria and fungi were detected in most samples in the cattle farmers' houses as well as in the cattle sheds. Aspergillus, Cladosporium, and Penicillium, which have been associated with adverse health effects, were three most prevalent fungal genera, and they took most of the total fungi (more than 69%). The microbial concentrations measured inside the cattle sheds were comparable to those in other reports. Nevertheless, the present arithmetic and geometric mean (GM) microbial concentrations exceeded the Korean guideline for total airborne bacteria at medical facilities ($800\;CFU\;m^{-3}$), the current GM residential indoor concentrations at houses, and the residential indoor levels reported in other countries. The present findings suggest the need for a strategy to reduce Korean cattle farmers' exposure to these microorganisms. In contrast to the microbes, it is suggested that the cattle shed is not an important microenvironment for $PM_{10}$ exposure. Two characteristics examined in this study (seasonal variation and summer survey period, i.e., temperature and humidity) were all important for the cattle farmers' occupational exposure to airborne microbes. The lack of constancy between highest and lowest concentrations of bioaerosols over the survey period further suggests the necessity of performing a long-term survey to better examine farmer exposure levels and their variability.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E4
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• pp.203-213
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• 2002

Receptor modeling is one of statistical methods to achieve reasonable air pollution strategies. In order to maintain and manage ambient air quality, it is necessary to identify sources and to apportion its sources for ambient particulate matters. The main purpose of the study was to survey seasonal trends of inorganic elements in the coarse and fine particles. Second, this study has attempted emission sources qualitatively by a receptor method, the PMF mo-del. After that. both PMF (positive matrix factorization) model and TTFA (target transformation factor analysis) model were applied to compare and to estimate mass contribution of coarse and fine particle sources at the receptor. A total of 138 sets of samples was collected from 1989 to 1996 by a low volume cascade impactor with 9 size fraction stages at Kyung Hee University in Korea. Sixteen chemical species (Si, Ca, Fe, K, Pb, Na, Zn, Mg, Ba, Ni, V, Mn, Cr, Br, Cu. Co) were characterized by XRF. The study result showed that the weighted arithmetic mean of coarse and fine particles were 51.3 and 54.4 $\mu\textrm{g}$/㎥, respectively. Contribution of both particle fractions were esti-mated using TTFA and PMF models. The number of estimated sources was seven according to TTFA model and 8 according to PMF model. Comparison of TTFA and PMF revealed that both methodologies exhibited similar trends in their contribution pattern. However, large differences between contributions were observed in some sour-ces. The results of this study may help to suggest control strategies in local countries where known source profiles do not exist.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.146-155
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• 2015

Objectives: The aims of this study were to set up benzene exposure matrices according to industry and process and to assess the risk of those occupational exposure to benzene. Methods: The benzene exposure matrices were assembled depending on industry and process, based on an exposure database provided by KOSHA(the Korean Occupational Safety and Health Agency), which was gathered from a workplace hazards evaluation program in Korea. These exposure matrices were assessed by Hallmark Risk Assessment tool. Results: The benzene was treated 412 industries sector(36%), 2,747 business places, and 471 industrial processes according to database. The arithmetic mean of past decade 8 hours time-weighted average of airborne benzene concentrations in the workplace was 0.10722 ppm. 1.07% of the total sample were greater than OEL, and 59.8% were showed less than the limit of detection. The highest risk values(Danger Value) were seen 36 industries including manufacture of general paints and similar product and 12 processes, such as other painting of manufacture of metal fabricated members. Exposure matrices based on employee exposure data base may provide exposure histories and can be used in epidemiological studies. Conclusions: It was found that more attentions should be paid to 36 among 412 industries and 12 of 471 processes, with a higher risk value.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.300-309
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• 2014

Objectives: The objective of this study is to evaluate microbial exposure hazards in the metal-working fluids(MWF) handling industry. Methods: Air quality parameters(airborne bacteria, fungi, endotoxin and oil mist) and bulk MWF in storage tanks were evaluated at 54 points at nine sites in South Korea. Results: The geometric means(GM) of culturable airborne bacteria, fungi, endotoxin and oil mist concentration were $133CFU/m^3$(n=376, range $7{\sim}6,510CFU/m^3$), $159CFU/m^3$(n=381, range $7{\sim}8,469CFU/m^3$), $8.06EU/m^3$(n=103, range $0.34{\sim}280.4EU/m^3$) and $0.20mg/m^3$(n=104, range $0.01{\sim}2.87mg/m^3$), respectively. The ratio of indoor to outdoor concentration was 2.7 for bacteria, 6.1 for endotoxin, and 4.8 for oil mist. Even though average airborne bacteria concentration did not exceed recommended exposure limits($1,000CFU/m^3$), MWF in the storage tanks was highly contaminated with bacteria(arithmetic mean $2.1{\times}10^6CFU/ml$) and exceeded recommended bacteria limits($10^5CFU/ml$). Conclusions: It is necessary for MWF handling workplaces to conduct periodical biohazard inspection of MWF storage tanks. Additionally, further research may be necessary to establish biological occupational exposure limits.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.1
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• pp.23-32
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• 1999

Deposition is one of the important removal mechanisms for the ambient aerosol, and it also leads to adverse environmental and economic impacts. The purpose of this study was to investigate chemical compositions and spatial distributions of fall-out aerosols. A total number of 340 samples were collected at 35 sampling sites in Suwon area from January to November, 1996. Twelve inorganic elements (Al, Ba, Cd, Cr, K, Pb, Sb, Zn, Cu, Fe, Ni, and V) and eight ionic components ($F^-$, Cl, $NO_3^-$, $SO_4^{2-}$, $Na^+$, $NH_4^+$, $Mg^{2+}$, and $Ca^{2+}$) were analyzed by AAS and IC, respectively. The monthly variation showed that the flux of fall-out particles was increased in the spring season(March, April, and May) and decreased from August to October. Arithmetic mean flux of fall-out particles was 176.8 kg/$ extrm{km}^2$/day during the study period. The fluxes of each chemical species were $SO_4^{2-}$ 12.414, $Ca^{2+}$ 7.369, $NO_3^-$ 5.812, $Cl^-$ 3.566, $NH_4^+$ 3.176, Fe 3.107 kg/$\textrm{km}^2$/day, and so on. By using a kriging analysis, spatial distribution pattern of those fluxes was intensively studied. Total fluxes estimated in Suwon city were 8424.72t/y of fall-out particles, 519.27t/y of $SO_4^{2-}$, 336.79t/y of $Ca^{2+}$,267.34 t/y of $NO_3^+$, 155.36t/y of $Cl^-$, 147.79t/y of Fe.