• Journal of dental hygiene science
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• v.9 no.1
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• pp.9-15
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• 2009

Aimed at office workers at their height of Temporomandibular joint disorder(TMD), organized self-filling questionnaires were distributed from January 7 to 26, 2008 to 216 workers in the fields of service, office work, and production in D metropolitan city, to get a proper recognition about prevention and treatment of TMD by observing how strongly occupational stress influence on them. The findings of the study were as follows: 1. For subjective symptoms of joint noise as TMD, occasional was 45.8% and often 12.0%, while for joint dislocation often was 12.0%. 41.2% said they feel pains while chewing, while 24.1% said they occasionally feel pains while not chewing. 2.8% said they often experience mouth-opening disorder. 2. For joint noise, answers were significantly different according to their ages, while 30's are at their height (P < 0.05). For joint dislocation, the shorter they worked the more they have it, so less than a year worker was 37.9%, while less than 3 years 31.0%, and less than 5 years 20.7%. For work type, daytime workers have more dislocation, 58.6%, than shift-workers 34.5% (P < 0.05, P < 0.01). For pains while chewing, the shorter they worked, the more they experienced, which is the same as mouth-opening disorder (P < 0.01). 3. Workers with mouth-opening disorder have much stress on occupational autonomy (P < 0.05) and workers with dislocation and pains while chewing have much stress on relation trouble (P < 0.05, P < 0.01). Workers with highly occupational insecurity has much trouble on dislocation and pains while chewing, while workers with dislocation have significantly much stress on unproper compensation (P < 0.05). 4. For who have joint dislocation, they have much stress on relation-trouble, occupational disorder, and un-proper compensation (P < 0.01, P < 0.05). Workers with pains while not chewing showed significant difference about occupational insecurity and relation troubles (P < 0.05, P < 0.01). Who have mouth-opening disorder showed significant difference about occupational autonomy (P < 0.05).

• Journal of dental hygiene science
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• v.14 no.4
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• pp.571-579
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• 2014

This study was conducted to provide basic data for improvement of the oral health management ability and the factors affecting oral health recognition and practice of 6th graders. The research subjects total 259 numbers of 6th grade students in two schools located in Changwon, it was investigated and analyzed with structured questionnaires. The collected data is analyzed by using IBM SPSS Statistics 19.0. The average oral health recognition score investigated were $3.19{\pm}0.41$, and $2.95{\pm}0.43$ for oral health practices. The oral health recognition was statistically significant differences by father's education (p<0.01), perceived oral health status (p<0.01), perceived grade (p<0.01), intention to attend oral health education (p<0.001). The oral health practices was statistically significant differences by father's education (p<0.01), perceived oral health status (p<0.001), perceived grade (p<0.05), parent's interest in child's toothbrushing (p<0.01), experience of oral health education (p<0.001), intention to attend oral health education (p<0.05). The factors that may improve the oral health recognition are in order of oral health practices, intention to attend oral health education, and parent's attention to child's tooth brushing. The factors that may improve the oral health practice was found to be in order of oral health recognition, parent's attention to child's tooth brushing, and perceived oral health status. As a result, in order to improve oral health management ability of 6th grade students, the surrounding environment, the attitude on oral care, the interest of oral, and the current disease status of oral health are required to be identified, then the oral health education program should be provided.

• Journal of dental hygiene science
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• v.14 no.2
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• pp.150-157
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• 2014

The aim of this study was to suggest a convenient method of monitoring the gingival state through plaque detection. Quantitative Light-Induced Fluorescence-Digital (QLF-D), which can assess mature plaque, can be used to assess the oral hygiene status of individuals and to establish an adequate intervention plans for them. The subjects of the study participated in the clinical training at Department of Dental Hygiene, N University. The subjects completed questionnaires on general characteristics and oral hygiene methods. Then, photographs of maxillary and mandibular anterior teeth of the subjects were taken using the QLF-D. After the oral examinations, gingival state was recorded according to the $L{\ddot{o}}e$ & Silness's Gingival Index (GI). In addition, a plaque control record was calculated in percentage using disclosing agent. The analysis of the relation between the plaque control record and the QLF-D scores showed positive correlation (r=0.638, p<0.001), and the analysis of the relation between the QLF-D scores and the gingival bleeding index scores also showed positive correlation (r=0.562, p<0.001). Besides, the study classified the participants into healthy gingiva group and the gingivitis group according to the classification criteria of GI, and when the difference of QLF-D scores between the groups was analyzed, the QLF-D scores were statistically significantly higher (t=-2.785, p=0.007) in the gingivitis group ($1.71{\pm}1.545$) than the healthy gingiva group ($0.74{\pm}1.290$). When the differences in mean values of the QLF-D scores were analyzed against and the gingival bleeding index scores, the QLF-D scores of 0 and 1 belonged to the category of normal gingival state while the QLF-D scores of 2, 3 and 4 belonged to the category of gingivitis state. Therefore, it is deemed that the red fluorescence detected by the QLF-D from the mature supragingival plaque can be used for monitoring the state of gingivitis.

• Journal of the Korean Chemical Society
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• v.59 no.5
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• pp.397-406
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• 2015

ZnO, II-VI group inorganic compound semi-conductor, has been receiving much attention due to its wide applications in various fields. Since the ZnO has 3.37 eV of a wide band gap and 60 meV of big excitation binding energy, it is well-known material for various uses such the optical property, a semi-conductor, magnetism, antibiosis, photocatalyst, etc. When applied in the field of photocatalyst, many research studies have been actively conducted regarding magnetic materials and the core-shell structure to take on the need of recycling used materials. In this paper, magnetic core-shell ZnFe₂O₄@SiO₂ nanoparticles (NPs) have been successfully synthesized through three steps. In order to analyze the structural characteristics of the synthesized substances, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR) were used. The spinel structure of ZnFe₂O₄ and the wurtzite structure of ZnO were confirmed by XRD, and ZnO production rate was confirmed through the analysis of different concentrations of the precursors. The surface change of the synthesized materials was confirmed by SEM. The formation of SiO₂ layer and the synthesis of ZnFe₂O₄@ZnO@SiO₂ NPs were finally verified through the bond of Fe-O, Zn-O and Si-O-Si by FT-IR. The magnetic property of the synthesized materials was analyzed through the vibrating sample magnetometer (VSM). The increase and decrease in the magnetism were respectively confirmed by the results of the formed ZnO and SiO₂ layer. The photocatalysis effect of the synthesized ZnFe₂O₄ @ZnO@SiO₂ NPs was experimented in a black box (dark room) using methylene blue (MB) under UV irradiation.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.97-106
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• 2000

In these respects the purpose of this research is manufacturing Co-W-P alloy thin film on the corning glass 2948 by electroless plating method using $NaH_2PO_2H_2O$ (sodium hypophosphite) as a reductant, and analyzing deposition rate, alloy composition, microstructure, and magnetic characteristics at various pH's and temperatures. For Co-P alloy thin film, the reductive deposition reaction occurred only in basic condition, not in acidic condition. The deposition rate increased as the pH and temperature increased, and the optimum condition was found at the pH of 10 and the temperature of 8$0^{\circ}C$. Also magnetic characteristics was found to be most excellent at the pH of 9 and the temperature of 7$0^{\circ}C$, resulting in the coercive force of 870Oe and the squareness of 0.78. At this condition, the contents of P was 2.54% and the thickness of the film was 0.216$\mu\textrm{m}$. For crystal orientation, we could not observe fcc for $\beta$-Co. On the other hand, (1010), (0002), (1011) orientation of hcp for $\alpha$-Co was observed. We could confirm the formation of longitudinal magnetization from dominant (1010) and (1011) orientation of Co-P alloy. For Co-W-P alloy thin film, coercive force was 500Oe and squareness was 0.6. For crystal orientation, (0002) orientation of $\alpha$-Co was dominatly found. Then we could confirm the formation of perpendicular magnetization. The content of P was constant at 0.8$\pm$0.2% and the content of W increased as the concentration of Na$_2$WO$_4$increased. When the concentration of Na$_2$WO$_4$was 0.1mol/L, the composition of W was 20%. We observed the changes of magnetic characteristics and microstructure of thin film depositions of Co-W-P by the heat treatment. For heat treatment, the temperature was increased step by step to 10$0^{\circ}C$, 20$0^{\circ}C$, 30$0^{\circ}C$, and 40$0^{\circ}C$ and it took 1 hour at each step in the reductive condition of hydrogen gas. By the heat treatment, flatness of surface was improved, but there were no changes on the magnetic characteristics and the microstructures.

• Applied Chemistry for Engineering
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• v.8 no.4
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• pp.560-567
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• 1997

A new approach to obtain stable $W_1/O/W_2$ multiple emulsions has been studied ; The basis of the interfacial interaction between a PCL-PEO-PCL triblock copolymer and a lipophilic emulsifier in the dispersed oil phase was examined. $W_1/O/W_2$ multiple emulsions were prepared by the two-step method. Arlacel P-l35 was used as a liphophilic emulsifier and Synperonic PE/F 127 as a hydrophilic one. Eutanol-G was used as an oil phase. NaCl was encapsulated within the multiple emulsion droplets as the internal marker and its release rate studies were carried out. The suability of the multiple emulsions have been assessed by measuring Separation Ratios(%) and microscopic observations. The release of NaCl was significantly reduced in $W_1/O/W_2$ multiple emulsions containing PCL-PEO-PCL triblock copolymer(2k-4k-2k or 6k-4k-6k) in the oil phase. It may be concluded that the copolymer and the emulsifier form effective interfacial complex to enhance stability and to control the release rate. The effective diffusion coefficients of the NaCl were estimated as $2.64{\times}10^{-15}s$and $3.23{\times}10^{-16}gcm^2/s$ for the $W_1/O/W_2$ multiple emulsion containing 1.2 wt % of PCL-PEO-PCL triblock copolymers with compositions of 2k-4k-2k and 6k-4k-2k, respectively. The rate of release decreased with the increase of the initial concentration of NaCl. The results were examined in view of Higuchi mechanism. A kinetic model which is similar to the model for release of dispersed drugs from a polymeric matrix was found to be suitable for the release of NaCl from $W_1/O/W_2$ multiple emulsions.

• Journal of Life Science
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• v.20 no.10
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• pp.1532-1537
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• 2010

This study compared the inhibitory effects of methanol extracts from yellow and black soybeans (black soybean, Seomoktae and Seoritae) on mutagenicity using the Ames test and growth of human cancer cells (AGS human gastric adenocarcinoma, HT-29 human colon cancer, Hep 3B hepatocellular carcinoma cells). In the Ames test system using Salmonella typhimurium TA100, aflatoxin $B_1$ ($AFB_1$)-induced mutagenicity was significantly inhibited by treatments with the methanol extracts from either yellow or black soybeans in a dose dependent manner (p<0.05). The methanol extracts from various black soybeans tended to have a greater inhibitory effect compared to those from yellow soybeans. As for N-methyl-N'-nitro-N-nitrosoguamidine (MNNG)-induced mutagenicity, the methanol extracts (5 mg/assay) from black soybean, Seomoktae and Seoritae showed 51%, 61% and 53% inhibitory rates, respectively, indicating that Seomoktae, a type of black soybean, had a stronger antimutagenic activity against mutagens (both $AFB_1$ and MNNG). Methanol extracts from black soybeans showed an inhibitory rate of greater than 50% on the growth of human cancer cells (AGS, HT-29 and Hep 3B) and the inhibition was more effective in the methanol extract from Seomoktae. Our results suggested that the methanol extracts from black soybeans showed stronger inhibitory effects on mutagenicity and growth of cancer cells than those from yellow soybean. It is concluded that intake of black soybean can be recommended for improving health.

• Journal of Korean Home Economics Education Association
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• v.28 no.1
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• pp.19-39
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• 2016

The purpose of this study was to develop the safety theme-based integrated teaching learning process plans for the middle school Home Economics(HE) Instruction and ultimately to contribute for the middle school students to live their safe lives. To achieve the goals of this study, HE curriculum documents from the 1st to the 2015 revision were analyzed and a survey was conducted to identify the middle school students' current status of safety accidents and needs on the HE safety education. The respondents of the survey were the 512 students of one ${\bigcirc}{\bigcirc}$ Girls' Middle School in Busan. And then, the seven integrated themes were selected, each seven integrated theme-networks were formed, and safety theme-based Home Economics curriculum and learning materials were developed. The results of this study were as the follows. The safety education content has continually been included from the first HE curriculum of 1954 to the 2015 revised HE curriculum. The middle school student respondents highly needed the content of 'the methods to deal with sexual violence and prostitution prevention', 'suicide prevention', and 'bullying net' for the HE safety education. All the 42 items were needed for the HE safety education by the respondents. The safety theme-based HE teaching learning process plans developed finally included the seven integrated themes, which were (1) dietary life safety, (2) adolescents' sex and safety, (3) adolescents' relationships with friends and safety, (4) family life and safety, (5) dwelling life and safety, (6) adolescents' egos and safety, and (7) social environment and safety. Each integrated theme consisted of three to six small themes, which amounted to total 28(for 35 lessons). Each small theme was presented with learning objectives and particular goals. The total 157 learning materials including the Home Economics curriculum were developed, which offered learning objectives and content for each safety theme, total 28 teaching and learning plans(for 35 lessons) were developed, which offered specific instructions for the easy implementation of the curriculum in the classroom, 28 PPTs, 25 film materials, four reading materials, 61 workbooks, 14 activity sheets, 16 evaluation sheets, 3 test sheets, 2 reference materials, and 4 learning material models(the refrigerator model, traffic lights for discussions, food tray model and stickers, and food mileage card). In this study, the safety education themes of 'clothing life and safety', 'conflict and safety', 'professional life and safety', and 'consumer and safety' were not addressed because these theme were not needed highly by the respondents. Therefore, for the further development of the teaching learning process plans for the HE safety education, it is necessary to develop and evaluate the teaching learning process plans to address the themes of 'clothing life and safety', 'conflict and safety', 'professional life and safety', and 'consumer and safety'.

• Journal of Korean Home Economics Education Association
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• v.32 no.2
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• pp.59-76
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• 2020

The purpose of this study was to develop and evaluate the teaching/learning process plan of 'housing culture and practical space use' for home economics in middle school according to the problem based learning(PBL) model. The plan consisting of 4-lessons has been developed and implemented following the steps of ADDIE model. Various activity materials (4 scenarios, 6 individual activity sheets, 10 reading texts, and 5 working resources) and visual materials (4 sets of ppt and 4 moving pictures) as well as questionnaire were developed for the 4-session lessons. The plans were implemented to a single class of 21 junior students at H middle school in rural area, Kyeongnam, from 1^st to 12^th of April, 2019. Students highly enjoyed and were satisfied with the whole 4-lessons in aspects such as understanding of the contents, adequacy of materials and activities, and usefulness in one's own daily life. Additionally, they have more actively participated in the lessons than usual and even interested in learning more of such lessons. Students also reported that they highly accomplished the goal of each lesson as well as overall objectives. They showed interest in the major part of PBL lesson such as scenario and group activities. And they engaged themselves in drawing the share housing space plan with '5D planner' web program which they described as the best part of the lessons. The teaching/learning process plan developed in this study may be used as a theme of maker education, which is emerging these days. It can be concluded that the PBL teaching/learning process plans for 'housing values and practical space use' would contribute to improving students' attitude on living with others and ability to manage one's individual life.

• Korean Journal of Health Education and Promotion
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• v.2 no.1
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• pp.93-106
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• 1984

Today, elderly people has desperately felt isolation and desolation due to the loss of activity at home and society by the change of social structure and the tendancy of nuclear family. The mutual-relationship between parants and their children is important to solve the problem of eldery people's isolation and desolation. The present study was conducted to investigate the status of mutual-communication by visiting, telephone and letter on 678 parents over 55 years of age and 1,316 their adult children from September 1st to 30th, 1982. It was investigated with questionaire by students. The frequency of communication from children to parents was highest in 25.4% by telephone and 21.6% by visiting, 4 times a month. Correspondence of letter showed only 18.1% in a year. The frequency of communication from parents to children was highest 16.1％ by telephone and 15.6％ by visiting, 4 times a month. Correspondence of letter showed only 11.3％ in a year. Urban parents showed higher frequency than rural parents by visiting and telephone, but lower by letter. The older age group of children showed higher frequency than the younger by visiting and telephone but 3rd decade was highest by letter. The younger age group of parents showed higher frequency than older age group. Mother was showed higher frequency than father by visiting and telephone, but father by letter. Higher education level group showed higher frequency than lower education level group. Merchants and factory workers showed the highest frequency by visiting and telephone, but officials by letter. Upper class group in socio-economic status showed higher frequency than lower class group generally, but lower class group dy letter from parents to children. The group within samedistrict between parents and children showed the highest frequency by visiting and telephone, but the group within long distance by letter.