• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.1049-1059
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• 2010

Objective : The purpose of this study was to examine the relationship of the general characteristics of parents to their children's oral health care. The subjects in this study were 117 parents and their children who resided in rural communities in the region of K. Methods : A survey was conducted with the consent of the parents from July 1 to 30, 2010. As for the survey on the children, the children who were in the lower grades were interviewed, and the upper graders filled out the questionnaires in person. A frequency analysis was carried out to find out the general characteristics of the parents and children, and x2-test was utilized to grasp the links between the general characteristics of the parents and the children's oral health care. A SPSS WIN 12.0 program was employed to analyze all the collected data. The findings of the study were as follows: Result : 1. As a result of investigating the relationship of the occupation of the parents to the children's regular dental checkup, the 71.8 percent of the entire children didn't get a dental checkup on a regular basis. The biggest percentage of the children of the self-employed parents(100%) got a regular dental checkup, and 90.9 percent of the children of the government workers did that(p<.05). 2. As a result of checking the relationship of the occupation of the parents to the children's dental-caries experiences, 39.3 percent of the whole children had no such experiences. The largest percentage of the children of the company employees(51.9%) had dental-caries experiences(p<.05). 3. Concerning the links between the academic credential of the parents and the children's toothbrushing method, the biggest percentage of the children(40.2%) brushed their teeth up and down. The largest rate of the children whose parents were high-school graduates(41.5%) brushed their teeth in that way(p<.05). 4. Regarding the links between the toothbrushing time of the parents and the children's view, 43.6 percent found their parents to take good care of their teeth to make them clean. 60 percent whose parents brushed their teeth after having breakfast and dinner took the best view(p<.001). 5. As for the oral-health education experiences of the parents and a time for the children's change of toothbrushes, 29.1 percent changed their toothbrushes every two months, and 29.1 percent did that not on a regular basis but when the bristles of their toothbrushes got bent(p<.05). Conclusions : The above-mentioned findings suggest that in order to promote children's oral health in consideration of the characteristics of their parents, children should be urged to get a regular dental checkup, and the development of oral-health education programs in which parents and children can participate together is urgently required.

• Journal of Embryo Transfer
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• v.6 no.2
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• pp.1-17
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• 1991

It is widely recognized that the embryonic or fetal loss after breeding is common in the cattle and that it is an important factor affecting reproductive efficiency. The causes of this loss have been subject of extensive researches and the results indicate that the embryonic mortality may he primary factor responsible for low pregnancy rates in non-embryo transfer bovine populations as well as embryo transfer programs. However, it's causes are still not clearly understood. The embryonic mortality or pregnancy rate has been influenced by various embryonic and maternal effects related to genetic and environmental factors. The timing and extent of embryonic mortality vanes greatly according to authors and estimating methods, because it is difficult to make direct measurements. The major important factors that may influence the embryonic losses or pregnancy rates after embryo transfer can be summeirized. 1.When an embryo is transferred to unmated recipients, the contralateral transfer to corpus luteum results in a lower survival rate than ipsilateral deposition. When the embryos are transferred for the production of twin calves, their survivals and twin pregnancies have quite inconsistent according to the transfer methods either to the unmated-synchronized or already mated recipients and more works are needed to accurrately clarify the previous results. 2.Although embryos can be cultured in vitro some hours without the great declines in pregnancy rates, the rates differ markedly among culture times and media but may be improved by co-transfer systems. 3.Embryo developmental stages and quality grades clearly affect the survival rate following freezing and the pregnancy rate after transfer and the selection of embryos without chromosome abnormalities and of high fertile semen may also be considered to increase the pregnancy rates. 4.Many researches have attempted to relate the plasma progesterone levels to pregnancy rates and others have done either direct progesterone supplementation or luteal stimulation by hCG treatment in order to increase the pregnancy rates. However, these effects on pregnancy rates are inconsistent and also contradictory. 5.The asynchrony between donors or embryos and recipients may he a major cause of embryo death and low pregnancy rate and the sensitivity to uterine asynchyony differs in according to the quality and stages of embryos. 6.The extremes of poor or over nutrition during early pregnancy in the recipients are detrimental to the survival of embryos and the good body condition is required to prevent a reduejion of pregnancy rates. The uterine pathogens in embryonic mortality or fertility have been questioned but the infection of C.pyogenes and Campylobacter fetus is still important pathogens. 7.The heat stress during early pregnancy may reduce conceptus weight and possibly increase the embryonic mortality.

• Journal of Engineering Education Research
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• v.8 no.4
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• pp.52-63
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• 2005

National competitiveness is related directly to the strength of educational competitiveness of universities. Seoul National University (SNU) has been taking efforts to improve its competitiveness in University education in variety of ways and the classroom assessment is one key example of those. The current classroom assessment system practiced at universities is being used to evaluate courses and professors in charge by the university administration or evaluation committee. The classroom assessment system is not intended to put students and professors as the subject of the evaluation. In this case, the evaluation is intended wrongfully to rank the courses and evaluate professors' achievement by assigning grades on the lectures. Instead, a proper classroom assessment system should be targeted to improve the quality of lectures by encouraging communication among professor and students in the classroom. In this study, it was intended to investigate a suitable classroom assessment system to enhance the effectiveness of education, not to rank the courses and evaluate professors' achievement. For this purpose, research has been carried out to investigate opinions of professors at SNU on the criteria of classroom assessment and to analyze the criteria of classroom assessment at other domestic universities in Korea. The inquiries for feedback on the lecture by the student in the class was analyzed. The current classroom assessment system at SNU was reviewed and an improvement plan was devised to evaluate liberal art courses of engineering and science schools at SNU. In this research, the problems in the classroom assessment system was reviewed and improvement points were searched to utilize the classroom assessment system more effectively for the improvement of lecture quality.

• Journal of the Korean Geotechnical Society
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• v.33 no.10
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• pp.5-14
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• 2017

The hazard maps for predicting collapse on natural slopes consist of a combination of topographic, hydrological, and geological factors. Topographic factors are extracted from DEM, including aspect, slope, curvature, and topographic index. Hydrological factors, such as soil drainage, stream-power index, and wetness index are most important factors for slope instability. However, most of the urban areas are located on the plains and it is difficult to apply the hazard map using the topography and hydrological factors. In order to evaluate the risk of subsidence of flat and low slope areas, soil depth and groundwater level data were collected and used as a factor for interpretation. In addition, the reliability of the hazard map was compared with the disaster history of the study area (Gangnam-gu and Yeouido district). In the disaster map of the disaster prevention agency, the urban area was mostly classified as the stable area and did not reflect the collapse history. Soil depth, drainage conditions and groundwater level obtained from boreholes were added as input data of hazard map, and disaster vulnerability increased at the location where the actual subsidence points. In the study area where damage occurred, the moderate and low grades of the vulnerability of previous hazard map were 12% and 88%, respectively. While, the improved map showed 2% high grade, moderate grade 29%, low grade 66% and very low grade 2%. These results were similar to actual damage.

• The Journal of the Korean dental association
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• v.48 no.6
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• pp.469-477
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• 2010

The purpose of this study was to evaluate the effect of two dentin desensitizers and Er,Cr:YSGG laser for dentinal tubule occlusion. Twenty recently extracted single-rooted human teeth were used to obtain root dentinal fragments. The crowns were cut approximately 1mm below the cementum enamel junction(CEJ). A second cut was used to remove the apex of the root. Subsequently, a longitudinal cut was made in order to obtain 2 fragments from each root sample. The cementum from the cervical portion was removed using a high-speed diamond-coated bur in order to expose the dentin. To open dentinal tubules, forty samples were treated with 50% citric acid for 2 min and then rinsed under distilled water for 1 min. These were divided into four groups of ten samples each. The first group served as a control group. In group 2, the samples were irradiated with the Er,Cr:YSGG laser(Waterlase MD, Biolase, USA). In group 3, the samples were treated with Bisblock and ONE-STEP PLUS(Bisco, USA). In group 4, the samples were treated with Gluma comfort bond & Desensitizer(Heraeus Kulzer, Germany). All the samples were examined using Scanning electron microscopy(Hitachi, S-4700, Japan) with two different magnifications(X2000, X5000). These images were assessed by one examiner who was blind to the experimental procedure, using the index of smear layer removal. The distribution of smear layer removal grades was tested using Fisher's exact test. On the order hand, in order to evaluate the occluding effect of two dentin desensitizers and Er,Cr:YSGG laser, the number of exposed dentinal tubules was counted in each group. These were evaluated using the Kruskal-Wallis test with significance predetermined $\alpha$=0.05. There were statistically significant differences between the three groups(Er,Cr:YSGG laser, Bisblock+ONE-STEP PLUS, Gluma comfort bond & Desensitizer) and control group.

• Journal of The Korean Association For Science Education
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• v.38 no.5
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• pp.753-763
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• 2018

The image of scientists that learners have has an important impact on science learning and on science-related career choices. The image of the scientist was mainly analyzed using the drawing analysis method. Drawing analysis has limitations on drawing, mainly analyzing the external image of scientist. Science teachers' images of scientists and their perception of science-related careers are important factors in students' science learning and science-related career choices. However, research on science teachers is lacking. Therefore, the purpose of this study is to investigate the usefulness of measurement tools by developing and applying a scientist image measurement tool through the semantic analysis method, and to discuss the educational implications of the research by investigating the image of scientists and science-related professions of secondary pre-service science teachers. The subjects of the study were 79 male and 55 female for a total of 134 students in the 2nd and 3rd grades majoring in science education at a teachers college. The results of the research show that the image measurement tool consisted of four components: 'ability,' 'evaluation,' 'activity,' and 'emotion,' in 24 items. As a result of applying the developed measurement tool to the secondary pre-service science teachers, the image of the 'evaluation,' 'ability,' and 'activity' elements of the scientist were high, but 'emotion' was low. There was no statistically significant difference according to gender. It is found that science-related career perceive them as 'hard,' 'professional,' 'smart,' and 'complex.' In particular, male students perceive themselves as 'hard and difficult' while female students perceive it as 'challenging and complicated'. Finally, we discussed the usefulness of using the image measurement tool of the scientists, the image of the scientists of the secondary pre-service science teachers, and the educational implications on science-related career.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.928-934
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• 2009

The purpose of this study was to examine the possibility of making functional sulgitteok with Goami 2 rice, which is a rich that is high in dietary fiber. Sulgitteok was made by adding various amounts of Goami powder(25, 50, 75, and 100 %) to rice powder. Then, the sensory tests and other tests to measure color, texture and hardness were examined as a function of time and the moisture content in sulgitteok was measured to determine the quality and characteristics of different types of sulgitteok. The conclusions of these tests were as follows : In the sensory evaluation preference test of sulgitteok made with various amounts of Goami powder, the overall preference was the highest in sulgitteok made with 50% Goami powder (S2). In the difference test, the higher the amount of added Goami powder, the lower the grades were. The S4 group, which was made with Gomai powder, had a strongly unique odor compared with those made with rice powder, which smelled weaker. In terms of the color values of Gomai added sulgitteok, the higher the amount of added Gomai powder, the lower the lightness value of sulgitteok, where group S4 had the lowest value. In addition, the S4 group, which was made with Goami powder, had the hightest red and yellow color. The texture test indicated that sulgitteok containing a large amount of Goami powder were considerably harder compared with the control group. While every group containing Goami powder (S1, S2, S3 and S4) became harder during the first to the third day of the test, their hardness tended to drop after longer storage times. In the control group, the hardness continued to grow from the start up to the fifth day. After five days' there was a noticeable change in the moisture content in the different types of sulgitteok, with more water evaporating in the S3, S2, and S1 groups than in the S4 groups, which contained the highest amount of Goami powder. Group C, which contained no Goami powder, had the largest water evaporation. Sulgitteok that contained more Goami powder turned out to be more savory than baekseolgi made solely of rice powder. However, they were less preferable overall, since they were rated lower in terms of color, texture and other characteristics. Therefore, utilize Goami tteok as a functional ingredient in food for people with diabetes or obesity, further studies on additives that can provide a sticky texture and favorable color should be conducted. In addition, different types of ttoek such as pounded or boiled ones may be preferable to sulgitteok.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.14-20
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• 2012

Objective : Intracranial meningiomas are primarily benign tumors with a good prognosis. Although WHO grade II meningiomas are rare (2-10%), WHO grade II meningiomas have higher recurrence and mortality rates than benign. We evaluated the patient recurrence rate and investigated the prognostic factors of WHO grade II meningiomas. Methods : Between 1993 and 2005, 55 patients were diagnosed with WHO grade II meningiomas in our hospital. WHO grade II meningiomas (n=55) were compared with other WHO grades meningiomas (I, n=373; and III, n=20). The patients had a median age of 48.4 years (range, 14-17 years), a male-to-female ratio of 26 : 29, and a mean follow-up time of 45 months (range, 3-175 months). Results : In WHO grade II meningiomas, only the extent of resection was a significant prognostic factor. Post-operative radiotherapy had no significant influence on tumor recurrence (p=0.053). The relative risk of recurrence was significantly higher in WHO grade II meningiomas with incomplete resection (10/27, RR=37%) than in WHO grade II meningiomas with complete resection (4/28, RR=14%) regardless of post-operative radiotherapy. In the incomplete resection group, Simpson grade III or IV had a significantly high risk of recurrence regardless of post-operative RT (n=3, RR=100%) However, if the degree of resection was Simpson grade II, the recurrence rate was similar to the complete resection group even though post-operative RT was not performed. Conclusion : Complete resection was the most powerful independent predictive factor of the recurrence rate in WHO grade II meningiomas. Post-operative adjuvant RT was not a significant factor in this study.

• Corrosion Science and Technology
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• v.11 no.1
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• pp.1-8
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• 2012

The development of martensitic grades which can be processed in continuous galvanizing lines requires the reduction of the oxides formed on the steel during the hot dip process. This reduction mechanism was investigated in detail by means of High Resolution Transmission Electron Microscopy (HR-TEM) of cross-sectional samples. Annealing of a martensitic steel in a 10% $H_2+N_2$ atmosphere with the dew point of $-35^{\circ}C$ resulted in the formation of a thin $_{C-X}MnO.SiO_{2}$ (x>1) oxide film and amorphous $_{a-X}MnO.SiO_{2}$ oxide particles on the surface. During the hot dip galvanizing in Zn-0.13%Al, the thin $_{C-X}MnO.SiO_{2}$ (x>1) oxide film was reduced by the Al. The $_{a-X}MnO.SiO_{2}$ (x<0.9) and $a-SiO_{2}$ oxides however remained embedded in the Zn coating close to the steel/coating interface. No $Fe_{2}Al_{5-X}Zn_{X}$ inhibition layer formation was observed. During hot dip galvanizing in Zn-0.20%Al, the $_{C-X}MnO.SiO_{2}$ (x>1) oxide film was also reduced and the amorphous $_{a-X}MnO.SiO_{2}$ and $a-SiO_{2}$ particles were embedded in the $Fe_{2}Al_{5-X}Zn_{X}$ inhibition layer formed at the steel/coating interface during hot dipping. The results clearly show that Al in the liquid Zn bath can reduce the crystalline $_{C-X}MnO.SiO_{2}$ (x>1) oxides but not the amorphous $_{a-X}MnO.SiO_{2}$ (x<0.9) and $a-SiO_{2}$ oxides. These oxides remain embedded in the Zn layer or in the inhibition layer, making it possible to apply a Zn or Zn-alloy coating on martensitic steel by hot dipping. The hot dipping process was also found to deteriorate the mechanical properties, independently of the Zn bath composition.

• Communications of Mathematical Education
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• v.34 no.3
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• pp.393-419
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• 2020

Trigonometry allows us to recognize the usefulness of mathematics through connection with real life and other disciplines, and lays the foundation for the concept of higher mathematics through connection with trigonometric functions. Since international comparisons on the trigonometry area of textbooks can give implications to trigonometry teaching and learning in Korea, this study attempted to compare trigonometry in textbooks in Korea, Australia and Finland. In this study, through the horizontal and vertical analysis presented by Charalambous et al.(2010), the objectives of the curriculum, content system, achievement standards, learning timing of trigonometry content, learning paths, and context of problems were analyzed. The order of learning in which the three countries expanded size of angle was similar, and there was a difference in the introduction of trigonometric functions and the continuity of grades dealing with trigonometry. In the learning path of textbooks on the definition method of trigonometric ratios, the unit circle method was developed from the triangle method to the trigonometric function. However, in Korea, after the explanation using the quadrant in middle school, the general angle and trigonometric functions were studied without expanding the angle. As a result of analyzing the context of the problem, the proportion of problems without context was the highest in all three countries, and the rate of camouflage context problem was twice as high in Korea as in Australia or Finland. Through this, the author suggest to include the unit circle method in the learning path in Korea, to present a problem that can emphasize the real-life context, to utilize technological tools, and to reconsider the ways and areas of the curriculum that deal with trigonometry.