• The Journal of the Korean dental association
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• v.55 no.10
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• pp.688-694
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• 2017

Objectives: This preliminary study compared the effects of glide path establishing instruments prior to substantial root canal preparation. Materials and Methods: Glide path was established by enlargement of the 2nd mesiobuccal root canal of Dentalike by using three kinds of glide path preparation nickel-titanium file; PathFile, One G and ProGlider. The pre- and post-instrumented Dentalikes were weighed in the resolution of 1 / 10mg. In addition, after glide path preparation, torque generated during shaping using the WavoOne file was measured. The data were analyzed by one-way ANOVA and Tukey post-hoc test at a significance level of 95%. Results: The ProGlider had the significantly larger amount of reduced weight than other instrument groups (p < 0.05). There was no significant difference between group of glide path preparation with ProGlider and without glide path preparation in maximum torque and total stress generation during the shaping with WaveOne. Conclusions: Glide path preparation instruments may have different efficiency according to their geometries. The Dentalike artificial teeth were revealed to have discrepancies in the size of root canals by microCT examination. It is impossible to make a meaningful judgment of the results due to the reliability or resolution problem of the root canal size of the artificial tooth selected as the standardized tooth.

• Journal of Sport and Applied Science
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• v.3 no.1
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• pp.1-14
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• 2019

Numerous types of sporting events have been hosted in Korea during the last decades. Sport events produce various types of data, and there is a clear necessity of storing and utilizing this information. From this background, the purpose of this study is to draw complex sports categories from international sport events life cycles in order to categorize standards of knowledges management system. This study utilized qualitative methods: expert groups discussion for overall life cycle steps and in-depth interviews for detail life cycle steps. The results show that there are several life cycle steps: bidding, preparation, operation, evaluation, post management steps. To be more specific, for the bidding step, there are check, plan, implementing detail phase; and the preparation step is based on event preparation Basis Build, event preparation implementation, test and supplementation phases. For the operation step, event operation system switch, event operation during the period, finish operation phases are deducted. Evaluation and post management step do not have detail phases. Efforts to store and utilize knowledge can be one of the starting points to make the operation of sport events efficiently.

• Journal of Information Science Theory and Practice
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• v.6 no.4
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• pp.54-64
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• 2018

This study aims to understand the information needs of Korean immigrant mothers in the United States for their high school children's college preparation. A content analysis was conducted for the messages posted to a "motherhood" forum on the MissyUSA website. In total, 754 posts were analyzed in terms of a child's grade, college preparation stage, type of post, and topic of post. The study found that there is a range of information needed at different stages in a child's education. Many of the demonstrated information needs showed similarities to those of other immigrant groups, but there were also community-specific themes, such as an emphasis on STEM (science, technology, engineering, and math) and standardized tests. The forum was mainly used for factual questions, not emotional support. We concluded that the findings of the study would help researchers in understanding immigrant information needs for the college application process and how information professionals and educators could combine the needs of different ethnic groups to create customized services for them.

• Korean journal of food and cookery science
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• v.8 no.2
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• pp.123-135
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• 1992

Time and temperature conditions, and microbiological qualities of six categories of menu items were assessed according to the process of food product Row in a 500 bed general hospital. The Harzard Analysis Critical Control Point (HACCP) system was applied to determine harzards, to assess their severity and risks, and to identity CCPs and memos for monitoring mem. The Critical Control Points identified for each category of menu items were: Meat Soup (Kyung Sang Do Gogi Guk): Pre-preparation, holding after pre-preration, and holding after cooking; Pot Stewed Stuffed Cabbage (Soe Yangbaechu Mali Chim): pre-preparation, holding after Pre-preparation, stuffing, cooking and holding after cooking; Boned Pork Sour Salad (Doeji Suyuk Muchim): Pre-preparation, holding after pre-preparation, and post-preparation after cooking; Sauteed Pork Ball (Jeyuk Wanja Jon): pre-preparation, holding after pre-preparation, shaping, and holding after cooking; Stir-fried Fragrant Mushroom (Pyogo Bosot Bokkum): basic ingredients, Pre-preparation, holding after pre-preparation, and holding after cooking; and Fried Corn with Vegetables (Oksusu Yachae Tuigim): pre-preparation, holding after pre-preparation, mixing, and holding after cooking.

• Restorative Dentistry and Endodontics
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• v.29 no.4
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• pp.378-385
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• 2004

The purpose of this study was to compare the effects of preparation with GT files and profiles .04 in shaping of root canals and reconstruct the three-dimensional root canal system using micro computed tomography 40 canals of the extracted human mandibular molars were used, and randomly distributed into two experimental groups. In group 1. canals were prepared by GT files. In group 2, Profiles .04. were used. Apical preparation size was #30. For each tooth pre and post operative cross-sectional images were obtained by the micro CT at 50 micron intervals. Pre and post operative cross-sectional images of 1, 2, 3, 5, and 8mm from the apex were compared. For each section. canal area and centering ratio were determined. For each tooth pre- and post-operative root canal volume from the furcation to the apex of the roots was calculated by three-dimensional image software. Following results were obtained: 1. At 8mm from the apex, area of dentin removed by GT rotary file was significantly larger than that by Profile .04. And at the other levels there was not a significant difference. 2. There was a trend for GT rotary file to remain more centered in the canals than Profile .04 at all levels. But at 3mm level. there was a statistically significant difference. 3. In root canal volume increments after instrumentation, there was no significant difference between two groups.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.53.1-53.11
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• 2020

Objectives: This study investigated the incidence of root dentin defects after the use of different post space preparation (PSP) drills. Materials and Methods: Seventy-two bovine incisors were selected and obtained 14-mm-long root sections. Twelve roots served as controls with no intervention (G1). The 60 root canals remaining were instrumented using the crown-down technique with the ProTaper Next system and obturated using the lateral condensation technique. Specimens were randomly distributed into 5 groups (n = 12) according to the operative steps performed: G2, root canal instrumentation and filling (I+F); G3, I+F and PSP with Gates-Glidden drills; G4, I+FI+F and PSP with Largo-Peeso reamers; G5, I+F and PSP with Exacto drill; and G6, I+F and PSP with WhitePost drill. Roots were sectioned at 3, 6, 9, and 12 mm from the apex, and digital images were captured. The presence of root dentin defects was recorded. Data were analyzed by the χ² test, with p < 0.05 considered to indicate statistical significance. Results: Root dentin defects were observed in 39.6% of the root sections. No defects were observed in G1. G5 had significantly more cracks and craze lines than G1, G2, and G3 (p < 0.05), and more fractures than G1, G2, G3, and G4 (p < 0.05). When all root sections were analyzed together, significantly more defects were observed at the 12-mm level than at the 3-mm level (p < 0.05). Conclusions: PSP drills caused defects in the root dentin. Gates-Glidden drills caused fewer root defects than Largo-Peeso reamers and Exacto drills.

• Journal of Korean Academy of Nursing Administration
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• v.10 no.4
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• pp.401-415
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• 2004

Purpose: The purpose of this study was to examine the effects of preceptor preparation education on the preceptor's role recognition and job satisfaction. Method: This study was designed as a pre-experimental, one group pre-test and post-test design. The subjects of this study were 44 preceptors who had the preceptor preparation education at a university hospital in Suwon, Korea. Data were collected from May 26th to June 15th, 2003. The collected data were analyzed using SPSS WIN 10.0 with paired t-test and Pearson's correlation. Result: The results were as follows; (a) After the preceptor preparation education, preceptor's role recognition increased significantly compared to before the preceptor preparation education (t=-4.910, p=.000), (b) After the preceptor preparation education, job satisfaction increased significantly compared to before the preceptor preparation education(t=-4.470, p=.000), (c) Preceptor's role recognition was significantly positive correlation with job satisfaction(r=.422, p=.004). Conclusion: The results of this study shows that preceptor preparation education was effective in increasing preceptor's role recognition and job satisfaction.

• Journal of Korean Academy of Rural Health Nursing
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• v.13 no.1
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• pp.3-19
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• 2018

Purpose: This study was done to identify effects of preparation for death and depression on geriatric quality of life in rural communities and to identify whether preparation for death has a moderating effect on the relationship between depression and geriatric quality of life. Methods: Data from 210 rural elders over 65 years of age were obtained through face-to-face interviews with the elders and were analyzed using SPSS 22.0 program. Results: Quality of life of elders who had prepared for death was lower than for elders who had not prepared for death. Elders with higher psychological preparation for death had a higher quality of life. Ritual preparation for death had negative effects but they were not statistically significant. Psychological preparation for death had a moderating effect on depression and quality of life for elders in the rural community. The explanation power was 36.1% while ritual preparation for death had no moderating effect on either depression or quality of life. Conclusions: It is necessary to provide rural elders with intervention programs designed to improve positive thinking and attitudes to living considering religion in the process. Intervention programs to improve psychological preparation for death are also required to alleviate depression.

• Restorative Dentistry and Endodontics
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• v.48 no.1
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• pp.1.1-1.11
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• 2023

Objectives: This study evaluated the dentinal penetration depth of 2.5% sodium hypochlorite (NaOCl) in root canals with and without preparation and different irrigant activation protocols. Materials and Methods: Sixty-three bovine mandibular incisors were randomly allocated to 6 groups (n = 10): G1, preparation + conventional needle irrigation (CNI); G2, preparation + passive ultrasonic irrigation (PUI); G3, preparation + Odous Clean (OC); G4, no preparation + CNI; G5, no preparation + PUI; G6, no preparation + OC; and CG (negative control; n = 3). Samples were filled with crystal violet for 72 hours. Irrigant activation was performed. Samples were sectioned perpendicularly along the long axis, 3 mm and 7 mm from the apex. Images of the root thirds of each block were captured with a stereomicroscope and analyzed with an image analysis software. One-way analysis of variance, followed by the Tukey post hoc test, and the Student's t-test were used for data analysis, with a significance level of 5%. Results: The NaOCl penetration depth was similar when preparation was performed, regardless of the method of irrigation activation (p > 0.05). In the groups without preparation, G6 showed greater NaOCl penetration depth (p < 0.05). The groups without preparation had a greater NaOCl penetration depth than those with preparation (p = 0.0019). Conclusions: The NaOCl penetration depth was similar in groups with root canal preparation. Without root canal preparation, OC allowed deeper NaOCl penetration. The groups without preparation had greater NaOCl penetration than those undergoing root canal preparation.

• Membrane and Water Treatment
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• v.13 no.4
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• pp.191-199
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• 2022

In industrial production, the development of traditional polyamide nanofiltration (NF) membrane was limited due to its poor oxidation resistance, complex preparation process and high cost. In this study, a composite NF membrane with high flux, high separation performance, high oxidation resistance and simple process preparation was prepared by the method of dilute solution dip coating. And the sulfonated polysulfone was used for dip coating. The results indicated that the concentration of glycerin, the pore size of the based membrane, the composition of the coating solution, and the post-treatment process had important effects on the structure and performance of the composite NF membrane. The composite NF membrane prepared without glycerol protecting based membrane had a low flux, when the concentration of glycerin increased from 5% to 15%, the pure water flux of the composite NF membrane increased from 46.4 LMH to 108.2 LMH, and the salt rejection rate did not change much. By optimizing the coating system, the rejection rate of Na₂SO₄ and PEG1000 was higher than 90%, the pure water flux was higher than 40 LMH (60psi), and it can withstand 20,000 ppm.h NaClO solution cleaning. When the post treatment processes was adjusted, the salt rejection rate of NaCl solution (250 ppm) reached 45.5%, and the flux reached 62.2 LMH.