• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.537-549
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• 1998

The purpose of this study was to evaluate the influence of root resection and retrograde cavity preparation methods on the apical leakage in endodontic surgery. To investigate the effect of various root resection and retrograde cavity preparation methods on the apical leakage, 71 roots of extracted human maxillary anterior teeth and 44 mesiobuccal roots of extracted human maxillary first molars were used. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. Three millimeters of each root was resected at a 45 degree angle or perpendicular to the long axis of the tooth according to the groups. Retrograde cavities were prepared with ultrasonic instruments or a slow-speed round bur, and occlusal access cavities were filled with zinc oxide eugenol cement. Three coats of clear nail polish were placed on the lateral and coronal surfaces of the specimens except the apical cut one millimeter. All the specimens were immerged in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using two-way ANOVA and Duncans Multiple Range Test. The results were as follows: 1. No statistically significant difference was observed between ultrasonic retrograde cavity preparation method and slow-speed round bur technique, without apical bevel (p>0.05). 2. Ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, with bevel (p<0.0001). 3. No statistically significant difference was found between beveled resected root surface and non-beveled resected root surface, with ultrasonic technique (p>0.05). 4. Non-beveled resected root surface showed significantly less apical leakage than beveled resected root surface, with slow-speed round bur technique (p<0.0001). 5. No statistically significant difference in apical leakage was found between the group of retrograde cavity prepared parallel to the long axis of the tooth and the group of one prepared perpendicular to the long axis of the tooth (p>0.05). 6. Regarding isthmus preparation, ultrasonic retrograde preparation method showed significantly less apical leakage than slow-speed round bur technique, in the mesiobuccal root of maxillary molar, without bevel (p<0.0001).

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.2
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• pp.70-80
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• 2003

We report the first direct measurement of $CO_2$ flux over Kwangneung broadleaf deciduous forest, one of the tower flux sites in KoFlux network. Eddy covariance system was installed on a 30 m tower along with other meteorological instruments from June to August in 2002. Although the study site was non-ideal (with valley-like terrain), turbulence characteristics from limited wind directions (i.e., 90$\pm$45$^{\circ}$) was not significantly different from those obtained at simple, homogeneous terrains with an ideal fetch. Despite very low rate of data retrieval, preliminary results from our analysis are encouraging and worthy of further investigation. Ignoring the role of advection terms, the averaged net ecosystem exchange (NEE) of $CO_2$ ranged from -1.2 to 0.7 mg m$^{-2}$ s$^{-1}$ from June to August in 2002. The effect of weak turbulence on nocturnal NEE was examined in terms of friction velocity (u*) along with the estimation of storage term. The effect of low uf u* NEE was obvious with a threshold value of about 0.2 m s$^{-1}$ . The contribution of storage term to nocturnal NEE was insignificant; suggesting that the $CO_2$ stored within the forest canopy at night was probably removed by the drainage flow along the hilly terrain. This could be also an artifact of uncertainty in calculations of storage term based on a single-level concentration. The hyperbolic light response curves explained ＞80% of variation in the observed NEE, indicating that $CO_2$ exchange at the site was notably light-dependent. Such a relationship can be used effectively in filling up the missing gaps in NEE data through the season. Finally, a simple scaling analysis based on a linear flow model suggested that advection might play a significant role in NEE evaluation at this site.

• Journal of Korean Home Economics Education Association
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• v.25 no.4
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• pp.63-77
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• 2013

The purpose of this study is to develop the home economics-relevant program on Korean traditional culture for adolescents from multicultural families for them for experience it directly, set up ego-identity and improve social adaptability. Further, we checked the effectiveness and efficiency of the developed program. First we developed the program composed of a total of 12 sessions based on experiencing Korean culture. It consists of largely 5 madang(parts) centered on themes such as Eowool madang, Hangeul madang, Play madang, Cooking madang and hostory madang. We ran the developed program for 3 months targeting a total of 18 persons composed of the adolescents from multicultural families and their mothers residing in S city of eastern area of Jeonnam province. We measured the participants' ego-identity, social adaptibility and participation satisfaction to examine the effectiveness of the program. The results of pre-test, post-test and satisfaction which are evaluation instruments used in this program are as follows. First, it appeared that the self-identity of the adolescent of multicultural families inceased by 0.30 from average score of 3.03 before the participation in the program to 3.33 after the participation. Social adaptability increased by 0.30 from average 3.11 before the participation to 3.41 after the participation. Second, in the program participation satisfaction, it appeared that first the middle satisfaction marked average 3.30 which exceeded median value at 3.00, meaning a little high satisfaction, whereas the final satisfaction had an averagescore of 4.03, which means a big satisfaction concerning the program participation. The results indicated that the home economics-relevant program was effective in improving the ego-identity and social adaptability of adolescents from multicultural families and supporting a role of as a member of Korean family.

• Journal of The Korean Association For Science Education
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• v.20 no.4
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• pp.542-561
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• 2000

The purpose of this study was to investigate the relationships among elementary school teachers' high school and college backgrounds in science, their attitudes toward teaching science, their science teaching efficacy beliefs, and their instructional strategies. Both quantitative and qualitative research methodologies, were utilized in this study. This paper, however, presents only the results of the quantitative data analysis while expecting to report the qualitative data analysis outcomes afterwards. Four instruments were used to ascertain information concerning teachers' backgrounds in science(the number of high school science courses they took and the grades of courses, the number of college science courses and grades, the number of college science methods courses and grades), attitudes toward teaching science, science teaching self-efficacy beliefs(personal science teaching efficacy and science teaching outcome expectancy), and their instructional strategies(indirect, direct, and mixed methods). A sample of 340 practicing elementary school teachers participated in this study. To determine statistically significant results, Pearson's correlation coefficient was used to relate teachers' backgrounds in science, attitudes toward teaching science, science teaching self-efficacy beliefs and their instructional strategies. The correlation coefficients were statistically significant regarding four variables, teachers' backgrounds in science, attitudes toward teaching science, science teaching self-efficacy beliefs, and instructional strategies investigated in this study. These results can be interpreted that programs of teacher preparations and trainings which include science and science methods courses should help prospective and practicing teachers change in their attitudes and beliefs toward science teaching. It is expected that future studies concerning teachers' attitudes, beliefs, and behaviors toward teaching science can help to improve science teacher education in Korea.

• Journal of The Korean Association For Science Education
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• v.35 no.2
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• pp.247-258
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• 2015

Students are engaged in classroom learning, and classroom learning occurs not only through conversation but also through nonverbal behavior. In science classrooms especially, there are meaningful nonverbal behaviors such as practical activities like observation and measurement. But these behaviors have not been properly investigated by existing instruments that try to measure students' engagement. This study aims to develop a new instrument for analyzing students' behavioral engagement especially in science classrooms. The method of developing the instrument was structured along three steps. First, student behaviors have been classified into fourteen categories through literature review and a series of observation of elementary science classroom. Second, based on these, a framework for analyzing student behavioral engagement has been developed. With the framework, every student moment could be labeled as Participatory Speech or Participatory Silence or Non-Participatory Speech or Non-Participatory Silence. Third, an instrument to which the framework is applied has been developed by using Microsoft Excel. As a trial, two fourth-grade students in elementary science class were analyzed with this instrument. The results of the trial analysis shows that the longest period of a science lesson was occupied by Participatory Silence (63% and 72%). Among the participatory silence, 'listening' was the most common (51% and 42% of the trial lesson) and 'observing' which is a specific behavior to science was the fourth position (17% and 17% of the trial lesson). It is expected that the developed instrument could be used in improving our understanding of the patterns of student engagement in science classrooms.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.1
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• pp.261-284
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• 2018

The current international legal system does not provide a safeguard against the militarization and the weaponization of outer space. Although the term "peaceful use of outer space" in the 1967 Outer Space Treaty(OST) appears in official government statements or in multilateral space treaties, it is still without an authoritative definition in reviewing national practices. The ambiguous ban on weapons in Article IV of the OST allows countries to loophole on the deployment of other weapons other than nuclear weapons. Meanwhile "Draft Treaty on the Prevention of the Placement of Weapon in Outer Space and of the Threat or Use of Force against Outer Space Objects(PPWT)" to Conference on Disarmament (CD) commissioned by the UN General Assembly's Special Session jointly submitted by China and Russia in 2008 and later revised in 2014, attempting to define and prohibit the proliferation of weapons in outer space and provided definitions of prohibited weapons, are opposed by the US on the grounds that currently there is no arms race in outer space. Some experts support a hard law approach in which binding laws aimed at ultimately creating integrated and binding legal instruments in all aspects of the use of outer space should be adopted to regulate the military use of space. However as a temporary measure the soft law guidelines should be developed for the non liquiet, a situation where there is no applicable law. The soft law could be used to create support for the declaration of the treaties and to create international customary law. For example, the 1963 Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space that regulates the activities of the state in the exploration and use of the universe, and the 1992 Principles Relevant to the Use of Nuclear Power Sources in Outer Space will illustrated. While substantial portions of the former was codified later in the 1967 OST, the latter which, although written in somewhat mandatory terms, have been consistently complied with by states, have arguably become part of customary international law. On November 12, 1974, the General Assembly reaffirmed that the development of international law may be reflected inter alia, by declarations and resolutions of the General Assembly which may to that extent be taken into consideration by the International Court of Justice.

• The Journal of Korean Academic Society of Nursing Education
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• v.7 no.2
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• pp.308-322
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• 2001

The purpose of this study was to investigate the relationship between climacteric symptoms and management of menopause of middle -aged women. The subjects of this study were 261 women(40 to 60 years old). Data were collected from Jun. 1 to Jul. 15, 2001 by a structured questionnaire. The instruments employed were : 1) The Climacteric Symptoms Scale developed by Aeri Song and Eun soon Chung(1998). 2) The Management of Menopause Scale developed by Aeri Song(1997). The data were analyzed by the SPSS p.c. program using t-test, ANOVA and Pearson correlation coefficient. The results of the study were as follows : 1. Mean score of climacteric symptoms was $2.18{\pm}0.39$(Maximum 4, Minimum 1). The mean scores among the categories of climacteric symptoms, in descending order, were : a) physical and physiological reactions ($2.62{\pm}0.53$), b) social and family relationships ($2.23{\pm}0.50$), c) psychiatric and psychological reactions ($2.08{\pm}0.49$), d) relationship with sexual partner($1.73{\pm}0.54$), e) genitourinary reactions ($1.72{\pm}0.55$). 2. Mean score of management of menopause was $1.79{\pm}0.45$ (Maximum 4, Minimum 1). The mean scores among the categories of management of menopause, in descending order, were : a) dietary management($2.57{\pm}0.52$), b) self control ($2.24{\pm}0.57$), c) management of exercise and physical activity($2.14{\pm}0.75$), d) management of sex life($1.71{\pm}0.47$), e) management of professional health maintenance($1.61{\pm}0.59$). 3. There were statistically significant differences in the score of middle-aged women's self reported climacteric symptoms according to : a) occupation (t=-2.79, p<0.001) b) marriage state (t=-2.29, p<0.05) c) age of menarche (F=4.66, p<0.001) d) method of Sanhujori (post natal care & treatment) (F=4.22, p<0.001) e) hormone replacement therapy (t=-3.09, p<0.05). From the above statistics, several significant findings were noted : a) There were more climacteric symptoms from those who were unemployed, those who had no partner or were divorced and those who started a menarche earlier. b) There were less climacteric symptoms reported from those on hormone replacement therapy and those who followed their parents or parents-in-law advice regarding Sanhujori (postnatal care) 4. There were statistically significant differences in the score of middle-aged women's self reported management of menopause according to : The educational background (F=7.63, p<0.001), religion (F=3.74, p<0.001), income (F=3.65, p<0.001), number of parity (F=4.87, p<0.001), method of Sanhujori(postnatal care) (F=5.73, p<0.001), period of Sanhujori (postnatal care) (F=2.81, p<0.05), hormone replacement therapy (t=3.81, p<0.001). Women with higher educational background, strong religion, higher income, large number of parity, managed their post natal care well, were on HRT, managed their menopause significantly better than the others who took part in the survey. 5. It will be noted from the above that women's degree of climacteric symptoms showed a negative correlation to the management of menopause(r=-0.2146, p<0.001). The findings shown above suggest the need to develop a variable management of menopause, in order to improve climacteric symptoms of middle-aged women. It is hoped that the above findings will stimulate more detailed research into this matter, and thereby enable guidance to be given to women going through the menopause to cope with it in a less stressful way.

• Korean Journal of Occupational Health Nursing
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• v.8 no.1
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• pp.22-41
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• 1999

This study intended to analyze the health promoting behaviors, compare their factors according to the shift pattern of duties of women workers who were working in the industrial workplace and present basic data in planning systematic and effective programs of health promotion for three-shift system and day-duty. Using Quota Sampling, 219 women workers were selected as subjects from 5 workshops which had 50 settled workers up to 300 and 10 factories which had more than 300 located in Taegu and Kyung-Book Province. Data were collected by means of questionnaire from September 12 to September 30, 1998. As the instruments of the study were used Health Promotion Lifestyle Profile(HPLP) which was adapted and adjusted by Seo, Y. O. for health promoting behavior, the one developed by Moon, J. S. (1990) for health-belief, the one developed by Sherer et al.(1982) and then adapted by Oh, H. S. for self-efficacy, and the one developed by Park, J. W. (1985) for social support. The analysis of data were performed with Cronbach's ${\chi}^2$-test, t-test, ANCOVA, Kendal tau, Pearson correlation, Stepwise Multiple Regression test using SPSS program. The results of the study are as follows : 1. There was a significant difference in age(${\chi}^2=32.46$, p=0.000), career (${\chi}^2=18.47$, p=0.000), working day(t=-3.18, p=0.000) by the shift pattern of duties in terms of socio-demographic characteristics. 2. There was a statistically significant difference between the two groups on the health promoting behaviors (t=2,52, p=0.012). The score of three-shift group on health promoting behaviors was 2.27, showing that it was lower by .13 than that of day-duty group(2.40). 3. ANCOVA involving age, career and working day as covariables, which had revealed significant difference before, showed that health promoting behaviors by the shift patterns of duties was significantly different(F=4.88, p=0.028). 4. In consideration of variables that have an influence on health promoting behavior by the shift pattern of duties, social support occupied 19.4% of health promoting behavior in the three-shift group and 22.5% including the sense of self-efficacy. In the day-duty group, social support occupied 34.4% of health promoting behavior. 5. The score of three-shift group(2.94) was significantly lower than that of day-duty group(3.12) in the perceived benefit of health-belief(t= -3.29, p=0.001), while the score of three-shift group (2.48) was significantly higher than that of day-duty group(2.24) in the perceived barrier (t=4.22, p=0.000). In the sense of self-efficacy(t=-4.20, p=0.000), the score of three-shift group(3.24) was significantly lower than that of day-duty group(3.53) while in social support(t=-4.56, p=0.000) the one of three-shift group(2.64) was significantly lower than that of day-duty group(2.88). The suggestions are as follows on the basis of the results of this study : 1. It is required to develop health promoting program that takes the shift pattern of duties of women workers into consideration. In addition, there are special demands on developing nursing strategies for health promoting behavior of three-shift workers. 2. It is required to develop specific strategies for social support which is the most significant factor to the health promoting behavior for women workers. 3. It is necessary to develop some programs for improving the sense of self-efficacy, social support, and health-belief of three-shift workers. To achieve these tasks, industrial nurses should play an active role and improve the ability of self-health care of women workers.

• Tuberculosis and Respiratory Diseases
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• v.60 no.1
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• pp.76-82
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• 2006

Background : The objective of this study was to understand sleep-related problems, and to determine whether the sleep questionnaires is a clinically useful method in patients who need polysomnography. Methods : Subjects were patients who performed polysomnography and who asked to answer a sleep questionnaires at the Sleep Disorders Clinic of St. Paul's Hospital, Catholic University of Korea. Baseline characteristics, past medical illness, behaviors during sleep-wake cycle, snoring, sleep-disordered breathing and symptoms of daytime sleepiness were analyzed to compare with data of polysomnography. Results : The study population included 1081 patients(849 men, 232 female), and their mean age was $44.2{\pm}12.8years$. Among these patients, 38.9% had an apnea-hypopnea index(AHI)<5, 27.9% had $5{\leq}AHI<20$, 13.2% had $20{\leq}AHI<40$, and 20.0% had $40{\leq}AHI$. The main problems for visiting our clinic were snoring(91.7%), sleep apnea(74.5%), excessive daytime sleepiness(8.0%), insomnia(4.3%), bruxism(1.1%) and attention deficit(0.5%). The mean value of frequency of interruptions of sleep was 1.6 and the most common reason was urination(46.3%). Epworth Sleepiness Scale(ESS) had a weak correlation with AHI(r=0.209, p<0.01). When we performed analysis of sleep questionnaires, there were significant differences in the mean values of AHI according to the severity of symptoms including snoring, daytime sleepiness, taking a nap and arousal state after wake(p<0.05). Conclusion : On the basis of statistical analysis of sleep questionnaires, the severity of subjective symptoms such as ESS, snoring, daytime sleepiness and arousal state after wake correlated with the AHI significantly. Therefore the sleep questionnaires can be useful instruments for prediction of the severity of sleep disorder, especially sleep-disordered breathing.

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.769-777
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• 2002

Using four components - nonionic surfactants, water, hydrocarbon oil and an alcohol as cosurfactant, 12 types of cleaning agents were prepared, and their physical properties such as surface tension, viscosity, electroconductivity and phase stability were measured. As the formulated cleaning agents have low surface tensions(30.5-31.1 dyne/cm) and low viscosities (1.6-7.2 c.p.), they are satisfied with the general physical properties of water-in-oil(W/O) microemulsions for their industrial use. They showed a tendency that their temperature range for stable one-phase microemulsion decreased in accordance with the increase of alcohol/surfactant(A/S) ratio in the formulations. However, the temperature range of one-phase microemulsion was much more affected by hydrophilic lipophillic balance(HLB) value of the nonionic surfactant which increased its temperature range and it increased in accordance with the higher HLB value in the formulations. And the maximum content of water which can keep stable one-phase W/O microemulsion was measured at each sample. In addition, their temperature range for stable one-phase microemulsion was also measured. It was confirmed that the selection of surfactant type was very important for formulating a cleaning agent, since the W/O microemulsion system with the nonionic surfactant of the lower HLB value showed better cleaning efficacy that of the higher HLB value for abietic acid as a soil, which was used for preparing a rosin-type flux. In the formulated cleaning agents with the increase of A/S ratio in the formulations, however, there was no significant difference in cleaning efficacy. It was investigated that the differences of their cleaning efficacy was affected by the change of the condition of temperature and sonicating frequency as important factors in the industrial cleaning. That is, the higher, their cleaning temperature and the lower, their sonicating frequency, the more increased, their cleaning efficacy. Furthermore, using optical instruments like UV/Visable Spectrophotometer and FT-IR Spectrometer, their cleaning efficacy for abietic acid was measured. The removal of soil from the contaminated rinse water was measured by gravity separation method in the rinse bath. As a result, the cleaning agent system having the nonionic surfactant of HLB value 6.4 showed over 85% water-oil separation efficacy at over $25^{\circ}C$. Therefore, it was demonstrated in this work that the formulating cleaning agents were very effective for cleaning and economical in the possible introduction of water recycling system.