• The korean journal of orthodontics
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• v.46 no.2
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• pp.73-80
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• 2016

Objective: The purpose of this study was to investigate the static (SFF) and kinetic frictional forces (KFF) in sliding mechanics of hybrid bracket systems that involve placing a conventional bracket (CB) or active self-ligating bracket (ASLB) on the maxillary anterior teeth (MXAT) and a passive SLB (PSLB) on the maxillary posterior teeth (MXPT). Methods: The samples consisted of two thoroughbred types (group 1, anterior-CB + posterior-CB; group 2, anterior-ASLB + posterior-ASLB) and four hybrid types (group 3, anterior-CB + posterior-PSLB-type 1; group 4, anterior-CB + posterior-PSLB-type 2; group 5, anterior-ASLB + posterior-PSLB-type 1; group 6, anterior-ASLB + posterior-PSLB-type 2) (n = 13 per group). After maxillary dentition alignment and maxillary first premolars removal in the stereolithographically-made typodont system, a $0.019{\times}0.025$-inch stainless steel wire was drawn through the right quadrant of the maxillary arch at 0.5 mm/min for 5 min. The SFF and KFF were measured with a mechanical testing machine and statistical analyses were performed. Results: Four different categories of SFF and KFF were observed among all groups (all p < 0.001). Group 1 demonstrated the highest SFF and KFF; groups 4 and 3 were second and third highest, respectively. The fourth category included groups 2, 5, and 6. Placing PSLBs on the MXPT resulted in significant SFF and KFF reductions in cases with CBs on the MXAT, but not in cases with ASLBs on the MXAT. Conclusions: These data might aid in the development of a hybrid bracket system that enables low-friction sliding of an archwire through the MXPT.

• Journal of dental hygiene science
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• v.20 no.3
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• pp.146-154
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• 2020

Background: The objective of this study is to investigate the needs and importance of basic core competencies required for future society by dental hygienists' viewpoints who are working in the clinical practices and to provide the fundamental data to develop the educational programs based on the competencies in the 21st century so as to enhance their working capability. Methods: A total of 38 questionnaires were used in this study, 3 questionnaires on the general characteristics (age, service years, main job functions) and those in 11 sub-factors of basic core competencies including 4 questionnaires on creativity, 3 on collaboration, 3 on communication, 3 on interpersonal relationship, 3 on problem-solving, 4 on resource control, 4 on self-control and development, 2 on vocational ethics, 3 on knowledge information utilization, 3 on global mind, and 3 on emotional intelligence. Self-reported survey was conducted in the dental hygienists who were working in Seoul and Gyeonggi Province and a total of 195 data were analyzed. Results: Vocational ethics, communication, and collaboration showed the highest on both importance and needs with 4.49 points and 4.34; 4.41 and 4.28; and 4.39 and 4.22, respectively, while global mind showed the lowest with 3.51 and 3.59. Upon Importance-Performance Analysis, 7 items were defined to require maintain the status including vocational ethics, communication, collaboration, interpersonal relationship, self-control, emotional intelligence, and problem-solving while 4 items with lower priority were resource control and development, knowledge information utilization, creativity, and global mind. Conclusion: Based on this study results that suggested the basic core competencies of dental hygienists in alignment with their jobs in the future society, competitive dental hygienists should be developed with the educational programs applied with these competencies.

• Journal of Ceramic Processing Research
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• v.19 no.5
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• pp.361-368
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• 2018

We investigated the interfacial properties of fluorocarbon self-assembled monolayers (FC-SAMs) with different alkyl chain lengths. It was found that the substrate characteristics were changed rapidly with the fabrication time and temperature of the SAM. FC-3SAM, which has the shortest alkyl chain in this study, showed a contact angle of $54.1^{\circ}$ when it was fabricated in an electric oven at $60^{\circ}C$ for the first minute. The FC-3SAM showed a contact angle of up to $76.9^{\circ}$ when it was fabricated in an electric oven at the same temperature condition for 180 minutes. FC-10SAM, which has the longest alkyl chain in this study, showed a contact angle of $64.7^{\circ}$ when it was fabricated at a temperature condition of $60^{\circ}C$ for 1 minute, and a contact angle of $98.7^{\circ}C$ at a temperature condition of $60^{\circ}C$ for 180 minutes. It was found that the FC-10SAM shows an increased contact angle and hydrophobic properties due to a well-aligned molecular structure resulting from a strong van der Waals force. In contrast, the FC-3SAM shows a small contact angle due to the intermolecular disorder resulting from a weak van der Waals force. The average roughness of FC-SAMs was investigated using AFM. The surface roughness of FC-SAMs, which verifies the results of contact angle, was confirmed. At a fabrication time of 120 minutes, the FC-10SAM showed an improvement in average roughness by 62% compared to that of FC-3SAM due to its good alignment.

• Journal of the Daesoon Academy of Sciences
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• v.26
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• pp.183-214
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• 2016

The purpose of this study is to promote the understanding of the objective of Daesoon Thought through 'examining the Objectives of Daesoonjinrihoe.' The objective of Daesoon thought was set when Kang Jeungsan Sangje descended to human world, upon the plea of divine sages, buddhas, and bodhisattvas, and determined to save the world and relieve people far and wide. For building an Earthly Paradise with Daesoon thought, Sangje carried out the great work of Reordering of the Universe for nine years and passed into heaven. Cho Jeongsan Doju, who received the heavenly religious orthodox through divine revelation from Sangje, served the late will of Sangje and established Main Tenets, Creeds, and objective of Daesoon thought. The objective set by Doju was continued to Park Wudang Dojeon and formed the Objectives of Daesoonjinrihoe. The Objectives of Daesoonjinrihoe consist of three sets of objectives in sequential order, which are related in organic, mutual beneficient, and integrative with one another. The Objectives starts from individual cultivation and expand into worldly reformation: 1)one's Spiritual transformation through Guarding against self-deception 2)Renewal of human beings through Realizing Earthly Immortality 3)Opening of new world through Building of Earthly Paradise. Also, in these Objectives of Daesoonjinrihoe, Three Realms of Heaven, Earth, and Humanity keep close relations to enter into new world. These Objectives are based on the 'thought of mutual beneficence' and are realized with Daesoon thought, which is the Dao of 'Crowned King' that goes beyond the previous thoughts of Confucianism, Buddhism and Taoism. Objectives of Daesoonjinrihoe have following details in each objective as following; (1) 'Guarding against self-deception-Spiritual Transformation' is for human nature. In Daesoon thought, human has the potential to restore conscience, which is true nature, and return to undefiled essence by 'guarding against self-deception'. In other words, it views that one can reach into the stage of spiritual alignment with the Dao once he recovers conscience through cultivation of Daesoonjinrihoe based on the idea of 'Guarding against self-deception'. (2) 'Realizing Earthly Immortality-Renewal of human beings' is for ideal human character. 'Realizing Earthly Immortality' in Daesoon Thought indicates the advent of ideal human beings called 'Dotong gunja'(virtuous beings who are aligned with the Dao). They are leaders who integrate politics and religion in helping people to renew themselves and make the world into Earthly Paradise. (3) 'Building an Earthly Paradise-Opening of new world' is for ideal society. Daesoon thought aims to making a peaceful world by creating an ideal society of heaven on this earth. Park Wudang Dojeon, who led Daesoonjinrihoe, emphasized the importance of Three Basic Activities: Spreading of Sangje's virtue, Edification, and Cultivation: and Three Major Activities: Aid and charity, Social welfare, and Education. Dojeon said "One should make effort to reach the utmost goodness through enlightening their bright virtue and cultivating their talent virtue." In this words, he made clear that the Objectives of Daesoonjinrihoe can be realized when people enlighten their bright virtue and cultivate themselves with their talent virtue. In conclusion, the Objectives of Daesoon thought were clarified of their meanings by Sangje, established into laws by Doju, and actualized by Dojoen in various activities of Daesoonjinrihoe.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.182-185
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• 2005

Satellite cameras are calibrated before launch in detail and in general, but it cannot be guaranteed that the geometry is not changing during launch and caused by thermal influence of the sun in the orbit. Modem satellite imaging systems are based on CCD-line sensors. Because of the required high sampling rate the length of used CCD-lines is limited. For reaching a sufficient swath width, some CCD-lines are combined to a longer virtual CCD-line. The images generated by the individual CCD-lines do overlap slightly and so they can be shifted in x- and y-direction in relation to a chosen reference image just based on tie points. For the alignment and difference in scale, control points are required. The resulting virtual image has only negligible errors in areas with very large difference in height caused by the difference in the location of the projection centers. Color images can be related to the joint panchromatic scenes just based on tie points. Pan-sharpened images may show only small color shifts in very mountainous areas and for moving objects. The direct sensor orientation has to be calibrated based on control points. Discrepancies in horizontal shift can only be separated from attitude discrepancies with a good three-dimensional control point distribution. For such a calibration a program based on geometric reconstruction of the sensor orientation is required. The approximations by 3D-affine transformation or direct linear transformation (DL n cannot be used. These methods do have also disadvantages for standard sensor orientation. The image orientation by geometric reconstruction can be improved by self calibration with additional parameters for the analysis and compensation of remaining systematic effects for example caused by a not linear CCD-line. The determined sensor geometry can be used for the generation? of rational polynomial coefficients, describing the sensor geometry by relations of polynomials of the ground coordinates X, Y and Z.

• Macromolecular Research
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• v.15 no.4
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• pp.348-356
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• 2007

The aim of this study was to fabricate a submicro-and micro-patterned fibronectin coated wafer for a cell culture, which allows the positions and dimensions of the attached cells to be controlled. A replica molding was made into silicon via a photomask in quartz, using E-beam lithography, and then fabricated a polydimethylsiloxane stamp using the designed silicon mold. Hexadecanethiol $[HS(CH_2){_{15}}CH_3]$, adsorbed on the raised plateau of the surface of polydimethylsiloxane stamp, was contact-printed to form self-assembled monolayers (SAMs) of hexadecanethiolate on the surface of an Au-coated glass wafer. In order to form another SAM for control of the surface wafer properties, a hydrophilic hexa (ethylene glycol) terminated alkanethiol $[HS(CH_2){_{11}}(OCH_2CH_2){_6}OH]$ was also synthesized. The structural changes were confirmed using UV and $^1H-NMR$ spectroscopies. A SAM terminated in the hexa(ethylene glycol) groups was subsequently formed on the bare gold remaining on the surface of the Aucoated glass wafer. In order to aid the attachment of cells, fibronectin was adsorbed onto the resulting wafer, with the pattern formed on the gold-coated wafer confirmed using immunofluorescence staining against fibronectin. Fibronectin was adsorbed only onto the SAMs terminated in the methyl groups of the substrate. The hexa (ethylene glycol)-terminated regions resisted the adsorption of protein. Human dermal fibroblasts (P=4), obtained from newborn foreskin, only attached to the fibronectin-coated, methyl-terminated hydrophobic regions of the patterned SAMs. N-HDFs were more actively adhered, and spread in a pattern spacing below $14{\mu}m$, rather than above $17{\mu}m$, could easily migrate on the substrate containing spacing of $10{\mu}m$ or less between the strip lines.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.65-72
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• 1998

The BTA drilling chip is better for deep hole drilling than other self-piloting with pad drilling chips because the large length to diameter ratio allows a unique cutting force dispersion and better supplies the high pressure fluid. Therefore the BTA is useful for many tasks, such as coolant hole drilling of large scale dies, as well as tube seat drilling, which is essential for the heat exchanger, and variable component drilling for automobiles. Deep hole drilling has several significant problems, such as hole deviation, hole over-size, circularity, straightness, and surface roughness. The reasons for these problems, which often result in quality short comings, are an alignment of the BTA drilling system and the unbalance of cutting force by work piece and tool shape. This paper analyzes the properties through an experiment which com¬pared single-edge BTA drills with multiple-edge BTA drills, as well as the shapes of the tools to cause an unbalance of cutting force, and its effect on the precision of the worked hole. Conclusions are as follows. 1) In SMSSC drilling, 60m/min of BTA with single and multi-edged tools proved the best cutting condition and the lowest wear character. 2) The roundness got a little worse as cutting speed was increased, but surface roughness was hot affected. 3) It was proved that the burnishing torque of both drills approached 26%. which is almost the same as the 24% insisted on by Griffiths, and the dispersion characteristic of the multi-edged BTA drill proved better than the single-edge BTA drill.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.10 no.2
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• pp.57-72
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• 2004

Background : The part to be very important that we make the physical development rightly at elementary school student days. Objective : This study investigated the relation of a physical health status which itself recognizes and an exercise performance situation out for an elementary school students. Methods : This cross-sectional study examined health and exercise performance status of 1,032 elementary school children. To examine children's a physical injury experience and injury occurrence characteristic and a personal computer utility condition, a body alignment status of the student which parents recognize and the relation of a fatigue and concentration level was an investigation with other factors. Results: An average age of the children was the 10.95 yr and an average weight was the 39.02 kg and an average height was the 145.17cm. The student to be experiencing currently an pain occurrence was 192(19.07%). It was most high to the grade 6(23.33%) compared with different grade(p<.01). Physical pain occurrence rate did not exist by gender(p>.05). There is most an pain occurrence region the ankle(38.0%). They had a 27.19% an physical injury experience of the students. A injury rate was revealed that were high as were the high grade(grade 6, 36.72%)(p<.01). A reason of the injury rate was high in a collision at the body(19.84%), falling down(18.68%) sequence at a traffic accident(22.96%)(p<.05). There were the significant relation to the school year the reason of the injury (p<.05). Currently there was the student to be taking special exercises a 57.97%. This that they have the relation with exercise with physical pain students to recognize 23.8%. The significant relation did not exist in the physical exercise execution and pain occurrence on the body(p>.05).

• Journal of the Optical Society of Korea
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• v.15 no.3
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• pp.289-292
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• 2011

Reactive mesogen (RM) is an organic liquid crystal molecule that can be self-aligned to have an optic axis of birefringence when coated over a polyimide alignment film. A free-standing optical wave-plate film consisting of RM and low-loss optical polymers was fabricated in this work, and the film was inserted across the polymer waveguide to form an integrated optical polarization converter. For convenient evaluation of the polarization converters, a waveguide polarizer and analyzer were fabricated in series. The polarization conversion efficiency was measured to be 25 dB for the wavelength range from 1520 to 1580 nm. The wave plate exhibited a temperature-dependent retardation of $4.5^{\circ}$ for a temperature change from 25 to $100^{\circ}C$.

• Journal of the Microelectronics and Packaging Society
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• v.19 no.4
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• pp.71-78
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• 2012

This paper describes trends in conventional scaling compared with advanced technologies such as 3D integration (3DI) and bumpless through-silicon via (TSV) processes, as well as the characteristics of CMOS (Complementary Metal Oxide Semiconductor) Logic device after thinning the wafers to less than $10{\mu}m$. Each module process including thinning, stacking, and TSV, is optimized for 3D Wafer-on-Wafer (WOW) application. Optimization results are discussed with valuable data in detail. Since vertical wiring of bumpless TSV can be connected directly to the upper and lower substrates by self-alignment, bumps are not necessary when TSV interconnects are used.