• Journal of dental hygiene science
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• v.12 no.5
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• pp.477-485
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• 2012

This study evaluate the influence of food staining food and bleaching on the color (CIELAB) and reflectivity of two-way (anterior & posterior) composite resin and flowable composite resin. There were 6 immersion media: kimchi, red pepper paste, blueberry, tea, curry and distilled water. A total of 36 specimens ($11{\times}11{\times}2$ mm) were prepared and immersed in each immersion media for 8 days at $37^{\circ}C$. Their color and reflectivity measured with the spectrophotometer at baseline and every 24 hours. Data from the color change and reflectivity were collected and subjected to statistical analysis by ANOVA, ANCOVA and RM-ANOVA. Curry showed the highest influence on color change and blueberry on brightness (p<0.001) on both resins. Bleaching after polishing made color change more than polishing or bleaching independently on two-way (anterior & posterior) composite resin, but not on flowable composite resin. It was suggested cleaning the mouth after taking curry and blueberry be needed to maintain the original color of composite resin.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.675-681
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• 2012

Korean Ministry of Health and Welfare started to implement oral health hub center to provide oral health preventive program and dental treatment to public, especially dental vulnerable class in 2006. But, there is no applicant area to implement it regardless of national budget arrangement in 2012. This study is aimed to investigate the reason not to be implemented and requirements of implementation. 293 among 1,000 public dental hygienists in the area where have not implemented oral health hub center were surveyed in Korea from April to July in 2012 through convenience sampling. The questionnaire consisted of the reason why oral health hub center have not been implemented, the requirement of implementation, duty area and duty position et al. After removal of insufficient responses, 217 questionnaires were analyzed by t-test and ANOVA using SPSS 20.0. The reason why oral health hub center have not been implemented were deficiency of the priority list as compared with other health program (72.4%), space insufficiency (71.4%), regional budget insufficiency (70.5%), will insufficiency of oral health promotion (70.5%) and manpower insufficiency (62.7%). The first requirement of implementation were space expansion and regional budget expansion, followed by reduction of record-originated and administrative tasks, understanding on oral health program of higher ranking public officials in health center, manpower expansion, reduction of other tasks than oral health program and volunteer source expansion. Budget insufficiency and manpower insufficiency in Metropolis were ranked higher than other area (p<0.05). The group not to discuss oral health hub center graded each reason not to be implemented significantly higher than the other group (p<0.05). We suggested that to promote the importance of public oral health program be needed to public and higher ranking public officials to implement oral health hub center. In addition, we insisted that more dental manpower and budget be needed for reduction of oral health inequity in metropolis.

• Journal of dental hygiene science
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• v.18 no.6
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• pp.349-356
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• 2018

The demand for medical care and welfare for patients with disabilities is expanding, and healthcare professionals are also increasingly interested in the need for medical care for patients with disabilities. The purpose of this study was to evaluate the competency of disabled patients' management and the education experience of dental hygiene students, who are the main players of oral health care for disabled patients. A total of 196 students in the dental hygiene department and 3rd and 4th grade students were surveyed using questionnaires. As a result, most of the students had a positive awareness of disabled patients; 84.7% answered with the need to train dental hygienists in specializing in handicapped patients, 76.5% were willing to attend seminars related to disabled patients after graduation, and 71.4% of the students provided dental treatment for patients with disabilities in curriculum and comparative curriculum. The students who provided treatment for disabled patients showed that their competence in most areas of knowledge of disabled patients, oral health education, and oral disease prevention was highly evaluated as significant. The competence of respondents who answered that the theoretical education was sufficient was significantly higher. Based on this, institutional support for the education of dentistry for disabled patients is needed, and sufficient theoretical education and practical training should be offered to foster personnel capable of contributing to the improvement in the oral health of patients with disabilities. In addition, in-depth discussions on the training of dental hygienists specialized in handicapped patients should be conducted.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.66-83
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• 2018

This article focuses how the materials of hatstrings of the 19th to 20th century gat, the Korean top hat for men among the collections of National Folk Museum of Korea, was transformed after port opening treaties with overseas since 1876. As a result of analyzing the materials of the hatstrings, amber, tortoiseshell, wood and bamboo as the traditional materials were used, and ivory, glass (soda glass, lead glass, alkali mixed glass) and plastics (cellulose nitrate, phenol-formaldehyde, polystyrene, acryl) were newly used for the hatstrings. Bamboo, wood and amber were the most frequently used materials. Bamboo was mainly used for the pipe of hatstring and were combined with beads and central decorations of other materials. This shows the trend of bamboo hatstring according to the simplification of the clothing and the culture by Regent Heungseon Daewongun. Ambers were used in the central decorations and beads and the origin of ambers was baltic amber just like the amber relics found in Korea. Compositions of glass were soda glass and alkali mixed glass which were excavated or handed down in Korea from ancient times to Joseon dynasty. But in the case of lead glass, Na2O was detected and it is considered to be a new type lead glass for crafts which came from overseas after port opening since 1876 because it showed the characteristic that it deviates from the lead glass component found in Korea. Plastics such as cellulose nitrate and phenol-formaldehyde were used as new synthetic materials to replace traditional materials such as tortoiseshell, amber, and coral as in the West. Cracks, crazing, crumbly and yellowing of cellulose nitrate of hatstrings were observed by deterioration. The survey of the materials of the 19th to 20th century hatstrings among the collections of National Folk Museum of Korea showed that the introduction of new materials such as glass and plastics were used to replace natural materials such as tortoiseshell and amber along with the use of traditional materials after port opening since 1876.

• Journal of Korean Academy of Dental Administration
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• v.5 no.1
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• pp.1-12
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• 2017

Although dental hygienists have performed chair-side assisting and other dental cares as well as preventive dental cares in Korea, medical technician law confines duties of dental hygienists as closed narrative. The aim of this study was to investigate difference in perception of duties of dental hygienists in dental clinic between dentists and dental hygiene students. A total of 245 copies of questionnaires were distributed to dentists and students by post-mail. Only 42 dentists and 30 students in an area replied these questionnaires about the present and future duties of dental hygienists after providing written consent. Both groups agreed that intra and extra oral X-ray taking, education about oral health behavior, instruction after dental treatment, chair-side assisting, consulting for patients, scaling, initial impression taking, management of dental materials and equipment, sterilization of equipment, and receiving dental bills are duties of dental hygienists. However, they had different perceptions about various dental treatments as duties of dental hygienists even if they were under instructions of a dentist, including infiltration anesthesia, filling in cavity, intramuscular injection, FC change, canal irrigation, orthodontic treatment including separating, ligature bracket bonding and removing, setting crown and bridge, making individual, removing implant screw, and so on. These findings demonstrated that there were different perceptions about duties of dental hygienists between dentists and dental hygiene students, especially on dental treatment.

• Journal of the Korean Society of Radiology
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• v.7 no.1
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• pp.17-24
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• 2013

This study estimate radiation biological danger factor by measuring patient's exposed dose and propose the low way of patient's exposed dose in panoramic radiography. We seek correcting constant of OSL dosimeter for minimize the error of exposed dose's measurement and measure the Left, Right crystalline lens, thyroid, directly included upper, lower lips, the maxillary bone and the center of photographing that indirect included in panoramic radiography by using the human body model standard phantom advised in ICRP. In result, the center of photographing's level of radiation maximum value is $413.67{\pm}6.53{\mu}Gy$ and each upper, lower lips is $217.80{\pm}2.98{\mu}Gy$, $215.33{\pm}2.61{\mu}Gy$. Also in panoramic radiography, indirect included Left, Right crystalline lens's level of radiation are $30.73{\pm}2.34{\mu}Gy$, $31.87{\pm}2.50{\mu}Gy$, and thyroid's level of measured exposed dose can cause effect of radiation biological and we need justifiable analysis about radiation defense rule and substantiation advised international organization for the low way of patient's exposed dose in panoramic radiography of dental clinic and we judge need the additional study about radiation defense organization for protect the systematize protocol's finance and around internal organs for minimize until accepted by many people that is technological, economical and social fact by using panoramic measurement.

• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.518-527
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• 2020

The aim of this study was to define the toxic effects of diuron and irgarol, which are new-antifouling agents, on the fertilization rate and normal embryogenesis rate in the sea urchin, Hemicentrotus pulcherrimus. In addition, the study was intended to confirm the hindrance of development in sea urchins. The fertilization rate of H. pulcherrimus was not decreased by the tested concentrations. However, the normal embryogenesis rate was decreased in a concentration-dependent manner. The 50% effective concentrations (EC₅₀) of normal embryogenesis rate were 7.12 mg L^-1 and 2.31 mg L^-1, respectively. As the embryos developed into pluteus larvae, after 18 h of exposure to diuron and irgarol at EC₅₀, development of the early gastrula stage was delayed, and significant developmental delays were observed after 24 h. After this, continuous developmental delays were observed in the process leading to the early gastrular, gastrular, early pluteus, and pluteus stages. Therefore, the toxic effects of diuron and irgarol on sea urchins were attributed to the delay in the developmental processes in the early life stages. Diuron and irgarol are highly persistent in the environment and have known-well toxic effects on various marine organisms including invertebrates, as shown in this study. Therefore, it is urgent to establish an environmental protection strategy to prevent the pollution of and preserve the marine environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.679-687
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• 2021

The purpose of the present study was to document the standardization and management process of interface terminology regarding the chief complaints, diagnoses, and procedures, including surgery in a four-hospital consortium. The process was proposed, discussed, modified, and finalized in 2016 by the Terminology Standardization Committee (TSC), consisting of personnel from four hospitals. A request regarding interface terminology was classified into one of four categories: 1) registration of a new term, 2) revision, 3) deleting an old term and registering a new term, and 4) deletion. A request was processed in the following order: 1) collecting testimonies from related departments and 2) voting by the TSC. At least five out of the seven possible members of the voting pool need to approve of it. Mapping to the reference terminology was performed by three independent medical information managers. All processes were performed online, and the voting and mapping results were collected automatically. This process made the decision-making process clear and fast. In addition, this made users receptive to the decision of the TSC. In the 16 months after the process was adopted, there were 126 new terms registered, 131 revisions, 40 deletions of an old term and the registration of a new term, and 1235 deletions.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.350-359
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• 2007

The egg development and morphological change of larvae and juveniles of the starry flounder, Platichthys stellatus were observed in laboratory. Fertilized eggs of the species, 1.09~1.19 mm (mean $1.13{\pm}0.03mm$, n=50) in diameter, were floating, colorless, transparent in shape and lacked in oil globules. The eggs hatched out 121 hours after fertilization at water temperature $8.2{\sim}11.2^{\circ}C$. The size of the hatched larvae were 2.58~2.89 mm (mean $2.67{\pm}0.09mm$) in total length, their mouth and anus were not open yet and myotome number was 14+27=41. Melanophore and xanthophore appeared on the notochord and digestive organ and the margin of membrane fin, on the yolk sac and eyes were lacking in pigment cells. 5 days after hatching the larvae attained 4.30~4.97 mm (mean$4.74{\pm}0.21mm$) in TL, and their mouth and anus were open. 10 days after hatching the larvae transformed to postlarval stage and they were 4.67~5.75 mm in TL (mean $5.30{\pm}0.31mm$), and absorbing the yolk completely. Feeding activity increased as the mouth became larger. At 23 days, the larvae attained 6.69~8.82 mm in TL (mean $7.85{\pm}0.75mm$), and the right eye was started moving to the left side of the head. At 52 days, the juveniles attained 10.99~17.06 mm in TL (mean $13.50{\pm}1.67mm$). The right eye was moved completely onto the left side. All of the fins had completed set of the fin rays (D. 64~67: A. 45~51: P. 11: V. 6: C. 19).

• Communications of Mathematical Education
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• v.25 no.2
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• pp.403-430
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• 2011

The purpose of the study was to investigate how the use of graphing calculators influence on forming students' mathematical concept of algebra, students' mathematical connection, and attitude toward mathematics. First, graphing calculators give instant feedback to students as they make students compare their written answers with the results, which helps students learn equations and linear inequalities for themselves. In respect of quadratic inequalities they help students to correct wrong concepts and understand fundamental concepts, and with regard to functions students can draw graphs more easily using graphing calculators, which means that the difficulty of drawing graphs can not be hindrance to student's learning functions. Moreover students could understand functions intuitively by using graphing calculators and explored math problems volunteerly. As a result, students were able to perceive faster the concepts of functions that they considered difficult and remain the concepts in their mind for a long time. Second, most of students could not think of connection among equations, equalities and functions. However, they could understand the connection among equations, equalities and functions more easily. Additionally students could focus on changing the real life into the algebraic expression by modeling without the fear of calculating, which made students relieve the burden of calculating and realize the usefulness of mathematics through the experience of solving the real-life problems. Third, we identified the change of six students' attitude through preliminary and an ex post facto attitude test. Five of six students came to have positive attitude toward mathematics, but only one student came to have negative attitude. However, all of the students showed positive attitude toward using graphing calculators in math class. That's because they could have more interest in mathematics by the strengthened and visualization of graphing calculators which helped them understand difficult algebraic concepts, which gave them a sense of achievement. Also, students could relieve the burden of calculating and have confidence. In a conclusion, using graphing calculators in algebra and function class has many advantages : formulating mathematics concepts, mathematical connection, and enhancing positive attitude toward mathematics. Therefore we need more research of the effect of using calculators, practical classroom materials, instruction models and assessment tools for graphing calculators. Lastly We need to make the classroom environment more adequate for using graphing calculators in math classes.