• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.42-51
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• 2022

Esthetic restoration of maxillary anterior implant heavily depends on the direction of installation of implant fixture. In patients with malpositioned implant, it is crucial to communicate the limitations of prosthetic outcome with the patient before starting on a restoration. To facilitate the communication, three-dimensional virtual representation by superimposing facial and intraoral digital scans with Computed Tomography (CT, dicom file) was used for visualization of the limitations of prosthesis. Through digital diagnostic wax-up, the profile of right maxillary anterior incisor implant was expected to be protrusive, which the patient was not satisfied with. Since the patient already had done root canal treatment on left maxillary anterior incisor due to previous trauma, a new prosthetic design including both right and left maxillary anterior incisors was presented to the patient. The second design was chosen and his comments were delivered to dental lab. The patient was satisfied with the new prosthesis, aesthetically and functionally.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.82-86
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• 2011

Lightweight aggregate which is composed of sintered polycrystalline materials usually has a certain portion of pores inside of it. Because of such a structural characteristics, it tends to that movement of water in aggregate shows an abnormal behavior against the change of outside environment. In general, water movement behavior is controlled by porosity, distribution of pore size; however, dense surface layer will also affect water movement behavior in case of artificially sintered aggregates. Factors affecting water movement behavior in the aggregate are pore distribution, pore shape, pre-wetting method, etc. In this study, absorption characteristics of aggregate under the pressure and absorption rate according to water dipping time are analyzed for the basis of pressure pumping of lightweight concrete. Two kinds of aggregates were used for the test: one is made by 'L' company in Germany and the other is of our own made at the pilot plant in Kyonggi University. Absorption rate of aggregate is measured according to water dipping time, vacuum pressure, and quenching condition. Absorption rate of aggregate with $300^{\circ}C$ quenching is higher than that of aggregate with 24 hr water dipping. Generally the more vacuum the higher water absorption rate. Water absorption rate of 'L' aggregate under -300 mmHg is 54 % higher than that of aggregate with 24 hr water dipping; however, only 2 % increase in water absorption was measured for the K622 and K73 which were of our own.

• Membrane Journal
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• v.28 no.1
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• pp.21-30
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• 2018

In this study, homogeneous and defect-free ceramic ultrafiltration membranes were fabricated by using the sol-gel method. A boehmite sol was synthesized and coated onto the surface of alumina hollow fiber microfiltration membranes. The effect of sol viscosity and surface tension on the coating layer homogeneity and thickness was investigated. The optimum coating repetition using pristine sol was determined to be 3 times, as the samples coated more than 4 times showed delamination. Fixing the coating repetition to 3 times, the effect of sintering temperature was also studied in this work. The samples sintered at $1000^{\circ}C$ exhibited the highest pure water permeability with the molecular weight cut-off (MWCO) of approximately 51 kDa (10 nm dextran), and the samples sintered at 600, $800^{\circ}C$ displayed the MWCO of 12 kDa (5 nm dextran). The ultrafiltration membranes prepared in this work showed competitive performance compared to the reported ceramic ultrafiltration membranes.

• Journal of Life Science
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• v.27 no.2
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• pp.241-246
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• 2017

The walls of guard cells have many different specialized features. Guard cells are present in leaves of bryophytes, ferns and almost all of the vascular plants. Guard cells show considerable morphological diversities. It is understood that the stomata show two types in terms of morphological characterizations of guard cells. The first type is only found in a few monocots including Poaceae and Cyperaceae. In rice and corn, guard cells have the morphological characteristics of dumbbell shape. The morphological characteristics of dumbbell shape always have subsidiary cells. The other type is found in every dicots and many monocots and they are kidney-shaped guard cells. The plants of kidney-shaped guard cells rarely have subsidiary cells except Commelina communis L. Therefore, it could be concluded that two types of the morphological characteristics of guard cells cannot divide according to monocots or dicots. Every plants in which stomatal characteristic features were all different, most of them belong to kidney-shaped guard cells. However in case of Sedum sarmentosum, guard cells were shown to be long and narrow lips type. In Tradescantia virginiana, the shape of guard cells could be called perfectly to half-moon type. Therefore, it could be concluded that kidney-shaped types are all different in some way, but dumbbell-shaped types are almost constant.

• Korean Journal of Heritage: History & Science
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• v.47 no.3
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• pp.4-23
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• 2014

Seokjojeon Hall is the Neoclassic style building situated in Deoksugung Palace, which was proposed by John McLeavy Brown who was a chief commissioner of the Daehan Empire and designed by John Reginald Hardings in 1897. Construction of the Seokjojeon Hall began in 1900 and completed in 1910 at the total cost of one million won. Decorating and furnishing of the interior was designed by Lovell and all the furniture of Seokjojeon Hall had been purchased from Maple&Co. The Maple&Co was the supplier of luxury furnitures and decorating items for luxurious residentials, hotels, embassies and the palaces and its headquarter was located in London. Ready-made furnitures were purchased as shown in the Maple's catalog. The designs and styles of the west were applied to Seokjojeon Hall. That is one of the aspects showing Daehan Imperial underwent a period of Westernization.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.495-501
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• 2016

The purpose of this study was to assess dental hygienists' awareness of medical technician jurisprudence. The study was conducted over a 2-month period from March 1 to May 1, 2016. A self-reported questionnaire was completed by 201 dental hygienists in Seoul, Gyeonggi, and Incheon province. The questionnaire consisted of items on the awareness of the jurisprudence pertaining to medical technician jurisprudence. Data were analyzed using the IBM SPSS Statistics ver. 19.0 program. We found that 32.8% of the respondents were aware of medical technician jurisprudence. Low awareness that result was due to "insufficient public relations efforts." The respondents thought that medical technician jurisprudence are inefficient in clinical settings. Of the dental hygienists, 75.9% replied that task distribution was unclear and 40.0% lacked awareness of the distribution of dentists' duties (40.0%). A total of 59.8% of respondents showed intention to participate in medical jurisprudence seminars. Of the dental hygienists, 77.0% agreed with the insert dental hygienists under medical jurisprudence category. In conclusion, dental hygienists' awareness of medical technician jurisprudence should be improved. In addition, the dental hygienist jurisprudence need to be revised regarding job status.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.349-355
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• 2014

The purpose of this study was to evaluate marginal gap of fixed dental prostheses (FDPs) fabricated by soft metal material with using dental computer aided design/computer aided manufacturing (CAD/CAM) system and to compare gap of its by a conventional method. Ten same cases of study models were manufactured and scanned for digital models fabricating. Ten FDPs were fabricated by soft metal material using dental CAD/CAM (SMB group). Then, ten FDPs were fabricated by cast metal using lost wax technique and casting method (LWC group). Marginal gap was measured by silicone replica technique. Gap was measured by digital microscope (${\times}160$). Mann-Whitney test for statistical analysis was executed (${\alpha}=0.05$). The mean (standard deviations) of marginal gap was $76.5{\mu}m$ (35.2) for the SMB group, and $82.9{\mu}m$ (22.1) for the LWC group. Statistically significant differences were not found between SMB and LWC. As results, FDPs fabricated by soft metal material were clinically acceptable range.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.575-580
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• 2023

This study was prevent the decrease in crop output by insect pests and spraying by application uniformity. A flight level 4 m height and 4-5 m/sec. speed are difficult to maintain with a agricultural drone for aerial application, which has been affected by the methods or environmental factors, such as changes in the wind. Therefore, which can allow a controlled application width and spray rate automatically and verified experimentally using drone. The sprayed particles began to decrease from about 3.75 m on the left and right sides of the spray nozzle. According to the number of particles, the effective spraying width was observed to be about 7.5 m, and it was verified that the proposed spraying system was effective in uniform control system.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.24 no.2
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• pp.86-100
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• 2015

To harmonize with the remaining natural teeth a dentist and technician make an effort to do. Dental ceramic perfectly reproduce the functionality and esthetic is so moved that will deliver to the patient. However It is not easy to overcome the problem. Actually, it can't have the same spectrum curve between different object. The spectrum curve and reflectance is a unique feature of an object like fingerprints. So it is not that the identification of spectral curves that we usually focuses color. We need to understand the process of matamerism makes something like a combination of color perception. In other word that will tell in our field with ceramic teeth of the patient wish to match the color matching process to simulate the cone in our retinas with the same combination.

• Korean Journal of Health Education and Promotion
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• v.21 no.1
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• pp.217-242
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• 2004

This study was carried out to measure job satisfaction and quality of life and to clarify the factors in job satisfaction which influence on quality of life of dental technicians, using developed tools for job satisfaction and WHOQOL-BREF for quality of life. The subjects for this study were 238 people who worked the in the Daegu-Kyungbuk area. The results of this study were as follows； the general characteristics that influenced job satisfaction, were especially education, hobbies, salary level, job career and work hours. The factors that influenced the quality of life, were especially Married status, hobbies, job position, and office hours. All subfactors in job satisfaction were related to each other. Growth-development factor was intensely related with recognition factor. Also, all subfactors in quality of life were in positive relation to each other, especially psychological domain was highly related with social domain. Factors of safety, recognition and accomplishment in job satisfaction intensely affected quality of life. Therefore, It is suggested that social recognition for dental technician should be promoted and it might be needed to adjust office hours and support hobby life.