• Title/Summary/Keyword: Flute

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Comparison of screw-in effect of three NiTi file systems used by undergraduates (학생들이 사용한 세 종류 NiTi file systems의 screw-in effect 비교)

  • Oh, Seung-Hei;Park, Jeong-Kil;Hur, Bock;Kim, Hyeon-Cheol
    • Restorative Dentistry and Endodontics
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    • v.31 no.6
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    • pp.477-484
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    • 2006
  • The purposes of this study were to compare the apical terminus width of simulated curved root canal prepared with three NiTi file systems used by undergraduates for evaluation the effects of flute angle and pitch or radial land on reducing screw-in effect and to determine more safe NiTi file system for inexperienced operators. Fifty inexperienced undergraduate students prepared 150 simulated curved root canals in resin blocks with three NiTi file systems ; ProFile$^{(R)}$, Hero Shaper$^{(R)}$, K3$^{TM}$. The electric motor set at a speed of 300 rpm and torque of 30 in a 16 : 1 reduction handpiece was used. The simulated root canal was prepared to ISO #25 sizes with each file system. The scanned images of pre- and post-instrumented canal of resin block were superimposed. To evaluate the screw-in effect of three NiTi file systems, apical terminus width of root canal was measured from superimposed images and statistical analysis was performed. There were significant differences in three NiTi flle systems. ProFile$^{(R)}$ had significantly smaller width than Hero Shaper$^{(R)}$ and K3$^{TM}$"" (P < 0.05), but no significant difference was observed between K3$^{TM}$ and Hero Shaper$^{(R)}$. Under the condition of this study, active file system (Hero SHaper$^{(R)}$, K3$^{TM}$) with variable pitch and helical angle had more screw-in effect than passive file system (ProFile$^{(R)}$) with constant pitch and helical angle. It seems that the radial lands play more important role in reducing screw-in effect.

Effect of adaptive movement on durability and working time of twisted file (Adaptive movement가 twisted file의 내구성과 작업 시간에 미치는 영향)

  • Lee, Sang-Ho;Park, So-Ra;Cho, Kyung-Mo;Park, Se-Hee;Kim, Jin-Woo
    • Journal of Dental Rehabilitation and Applied Science
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    • v.35 no.1
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    • pp.20-26
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    • 2019
  • Purpose: Recently TF-adaptive movement is developed in order to increase the durability of TF files. The purpose of this study was to assess the effects of adaptive movement on durability and performance of twisted files. Materials and Methods: Resin blocks simulating artificial J-shape canals were used for this study. In TFC group, TF-adaptive ML-1 (25/.08 size) files were used to prepare the canals under continuous rotation 500 rpm/4.0 Ncm. In TFA group, TF-adaptive ML-1 (25/.08 size) files were used to prepare the canals under adaptive movement. After preparing each artificial canal, TF files were observed under dental microscope for assessing existence of unwinding, distortion, and fracture. If unwinding of flute was observed, the number of artificial canals until unwinding of flute occurs was recorded. Required time until instruments reach working length and distance of unwinded portion of files from D0 were measured. All test results were conducted by Mann-Whitney U test at a 0.05 level of significance. Results: No Ni-Ti instrument's separation was observed. Number of resin blocks until file unwinding happens and working time was significantly high in TFA group compared to TF group. Distance of distortion from D0 didn't show significant difference between TFA, TF groups. Conclusion: The number of resin blocks prepared until unwinding happens and working time were significantly high in TFA group. The location of unwinding showed no significant difference between 2 groups. Adaptive movement increased the number of canals prepared until unwinding occurs and working time of twisted files.

Investigation on the Perception Changes of the Korean Music through Developing A Teaching Method for Samul-nori (사물놀이 지도법 개발과 이를 통한 국악의 인식 변화 연구)

  • Lee, Ka-Won;Kim, Young-Won
    • The Journal of the Korea Contents Association
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    • v.12 no.3
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    • pp.114-122
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    • 2012
  • Traditional music should be succeeded and developed through the systematic education since music represents culture and history of one country. In Korea, even through the importance of Korean traditional music has been emphasized through the seven times of revision of national curriculum, music education has been still Western-oriented. This study aims to make students have experience Uttari Samul-nori and investigate the perception changes about the Korean traditional music. It is ultimately expected that students inherit the Korean traditional music and further recreate our own traditional culture. Samul-nori class was organized in the regular music curriculum twice a week, for 10 hours and various activities were tried during that time. 1st-year high school students participated in this research and they were allowed to play Samul instruments directly and play the basic rhythm suggested in the newly designed curriculum. Before and after the research, the questionnaires were sent to examine the attitude changes toward the Korean traditional music. The result of the questionnaire are as follows: First, Samul-nori activities affect positively the students' interest in the Korean traditional music and Samul-nori itself. Second, Danso(short bamboo flute) education which has been implemented most frequently during the Korean music education, is not satisfactory to the students. Third, students were satisfied with the new teaching method of Samul-nori and most students wanted to continue to take Samul-nori class. Last, students recognized the importance of Korean traditional music education after the research activities.

Effect of Liner Component Coatings by Oxidized Starch on Properties of Corrugated Board (라이너지의 산화전분 코팅이 골판지의 물성에 미치는 영향)

  • Ahn, Byoung-Kuk;Ahn, Won-Yung
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.2
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    • pp.3-11
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    • 1998
  • Coating was carried out on liner components of B flute, single-wall corrugated board(SK180/S120/K200) to examine the effect of liner component coatings by oxidized starch on the properties of corrugated board. Both bursting strength and edgewise compression strength(ECS) of corrugated board were improved by coating of its liner components with oxidized starch. Bursting strength of corrugated board rapidly increased with an initial increase of coating weight, but as the coating weight further increased, there was no increase in bursting strength. The results showed 30.3% improvement for $2.32g/m^2$ coating on outside liner component, 36.8% improvement for $4.84g/m^2$ coating on inside liner component and 39.9% improvement for $7.16g/m^2$ coating on both liner components in bursting strength of corrugated board. Regardless of treated liner components, ECS of corrugated board was improved by coating of oxidized starch, and especially greater improvement was accomplished when corrugated board was coated on inside liner component or both liner components at low level of coating weight - 11.3% improvement for $1.58g/m^2$ coating on Inside liner component and 11.9% improvement for $2.99g/m^2$ coating on both liner components.

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THE EFFECT OF DIFFERENT FLUTE DESIGN AND TORQUE-CONTROLLED MOTOR ON THE SHAPING ABILITY OF SIMULATED RESIN ROOT CANALS (엔진의 토크 조절 능력과 니켈-티타늄 파일의 삭제 성향이 근관 성형에 미치는 영향)

  • Roh, Hyoung-Mee;Huh, Bock;Kim, Hyeon-Cheol;Park, Jeong-Kil
    • Restorative Dentistry and Endodontics
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    • v.30 no.6
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    • pp.486-492
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    • 2005
  • The purpose of this study was to compare the shaping ability of the two different Ni-Ti file systems and the two different engine systems in simulated canals. A total of four groups of each 10 were tested. Each group was instrumented with HeroShaper and Endo-Mate2 (Croup HE), HeroShaper and Tecnika (Croup HT), ProFile and Endo-Mate2 (Group PE), and ProFile and Tecnika (Croup PT). Canal preparation time was recorded. The images of pre- and post- instrumented root canals were scanned and superimposed. The amounts of increased width and centering ratio were measured and calculated at apical 1, 3 and 5mm levels. These data were statistically analyzed with one-way ANOVA and Duncan's multiple range test The results of this study were as fellows ; 1. Canal preparation time of HT group was the shortest (p<0.05). 2. The amount of increased canal width in HE group was significantly larger than PT group at apical 1mm level (p<0.05) At apical 3mm level, PT group was significantly smaller than other groups (p<0.05). At apical 5mm level, PE group was significantly larger than PT group (p<0.05). 3. The amount of centering ratio in HE group was significantly larger than other groups (p<0.05). At apical 5mm level, HT group was significantly larger than PE group and PT group (p<0.05). Under the condition of this study, torque-controlled endodontic motor is safer than no torque controlled motor, especially when the active file is used.

Shaping characteristics of two different motions nickel titanium file: a preliminary comparative study of surface profile and dentin chip (두 가지 다른 행정의 니켈 티타늄 파일의 성형 성상: 표면 성상, 상아질 삭편과 도말층에 대한 예비적 비교 연구)

  • Park, So-Ra;Park, Se-Hee;Cho, Kyung-Mo;Kim, Jin-Woo
    • Journal of Dental Rehabilitation and Applied Science
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    • v.30 no.2
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    • pp.121-130
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    • 2014
  • Purpose: To assess the surface profile of dentinal wall, dentin chips and smear layer during the canal shaping with rotary (ProTaper) and ProFile and reciprocating (WaveOne) nickel-titanium file. Materials and Methods: Sixty human extracted mandibular premolars and incisors with single canals were randomly selected. Three experimental groups (n = 20) were instrumented with ProTaper (F2), ProFile (25/.06), WaveOne (25/.08) with irrigation of 2.5% NaOCl. The dentin chips were collected from flute of file during each canal preparation. After canal preparation, roots were grinded and each group was divided into two subgroups (n = 10) for surface profile and smear layer of dentinal wall of shaped root canal. Each specimen was observed under scanning electron microscope for evaluating size of dentin chips, root canal surface recessions and smear layer. Scores of Smear layer were statistically analyzed using Kruskal Wallis test and Mann Whitney test at P = 0.05 level. Results: The size of dentin chips from ProFile, ProTaper and WaveOne was up to $7{\mu}m$, $6.5{\mu}m$, and$4{\mu}m$, respectively. In the surface profile, the width of surface irregularity was measured and Profile, ProTaper and WaveOne was up to $150{\mu}m$, $70{\mu}m$, and $80{\mu}m$, respectively. Completely cleaned root canals were not found. In the middle and apical third of the canals, WaveOne group showed higher smear layer score than ProFile and ProTaper groups (P < 0.05). Conclusion: Within limits of this study, reciprocating motion WaveOne group was not significant difference of shaping ability with the full-sequence ProFile and ProTaper systems except canal clearness of middle and apical third of root canal. When using WaveOne to shaping root canal, thorough root canal irrigation is recommended.

A Study on the 'Youngsan(靈山)' recorded in 『Songnamjabji(松南雜識)』 (『송남잡지(松南雜識)』에 기록된 '영산(靈山)'에 관한 연구)

  • Cho, Seog-Yeon
    • (The) Research of the performance art and culture
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    • no.40
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    • pp.269-305
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    • 2020
  • Youngsan is generally known as Pansori Danga(短歌). However, the contents of 'Yeongsan' in 『Songnamjabji』 are different. In 『Songnamjabji』, Cho Jaesam explained the contents related to 'Youngsan' using three kinds of poems: Shin Kwangsoo's poem, Baegho Imje's poem, Kim Myeongwon's poem. First, 'Ujo Youngsan' appears in Shin Kwangsoo's poem. Shin Kwangsoo wrote the (1750) when Yoo Jinhan's 『Manhwajib(晩華集)』(1754) was published. It is difficult to see the 'Ujo Youngsan', which appears in Shin Kwangsoo's poem written in a time when Pansori was not widely known, as the Pansori Danga. Second, Jo Jaesam called the music in Baegho Imje's poem 'Youngsan Dodeueum'. In 'Youngsan Dodeueum', flute and 'Dodeuli rhythm' were used. This fact is connected with , an instrumental music. , also a Buddhist term, continued to be used in the palace as well as among the people. Third, Cho Jaesam introduced Kim Myeongwon's poem in 'Yeongsan' part and called it 'Taryeong.' At that time, the term 'Taryeong' referred to both Pansori and Jeongga(正歌). Later, in the 19th century, 'Youngsan' was recorded as a term for the Danga to loosen the neck before Pansori began in earnest. In other words, the early 'Yeongsan' recorded in 『Songnamjabji』 was a Buddhist term, referring to the music of the upper class Seonbi, such as , Gasa(歌詞) and Sijo(時調). In 1855, when 『Songnamjabji』 was written, 'Youngsan' was used as a term used to refer to both Changbu-Music and Gagaek(歌客)-Music, mixed with the term 'Taryeong'. And as Pansori became popular, the term 'Taryeong' came to be called 'Pansori' and 'Youngsan' was used to refer to Pansori Danga. Therefore, all the records of 'Youngsan' should not be interpreted as Pansori Danga. This situation is closely related to religious and social change. The policy of worshipping Confucianism and suppressing Buddhism rejected the term 'Youngsan' which had a Buddhist meaning. In the middle of Joseon Dynasty, when Buddhism was suppressed, 'Youngsan' and 'Taryeong' were mixed. As Buddhism regrown in the late Joseon Dynasty, with the advent of Pansori, the term 'Youngsan' seems to be newly resettled in the sense of Danga. Pansori appeared in the 19th century and 'Yeongsan' was used as a Danga. And the reason should be regarded as this social and religious change.

Dreams of Admiral Yi Sun-sin (1545-1598) in Nanjung Ilgi (Diary in War Time) and Some Aspects of His Personality: From Jungian Viewpoint (≪난중일기≫에서 본 이순신의 꿈과 인격의 몇 가지 측면: 분석심리학적 입장에서)

  • Bou-Yong Rhi
    • Sim-seong Yeon-gu
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    • v.37 no.2
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    • pp.99-148
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    • 2022
  • This study aims at the psychological elucidation of some conscious aspects of the personality of Yi Sun-sin (1545-1598), the Korean national hero, and the unconscious teleologic meanings of his dreams mentioned in Nanjung Ilgi (Diary in War Time) from the viewpoint of analytical psychology of C.G. Jung. Yi Sun-sin was a man of discipline, incorporated with the spirit of Confucian filial piety, hyo (hsiao) and royalty, chung. He was a stern man but with a warm heart. In his diary, Yi Sun-sin poured forth his feelings of suffering, despair, and extreme solicitude caused by slanders of his political opponents, his grief for the loss of mother and son, and his worries about the fate of his country, which the Japanese invaders now plundered. The moon night offered him the opportunity to touch with his inner soul, by reciting poems, playing Korean string, 'Keomungo', and flute. Further, he widened his scope by asking for the answers from the 'Heaven' through divination and dream. Yi Sun-sin's attitude toward his mother who raised the future hero and maternal principles were considered in concern with the Jungian term 'mother complex'. Won Gyun, Yi Sun-sin's rival admiral, who persistently accused Yi Sun-sin of 'slanders,' certainly represents the unconscious shadow image of Yi Sun-sin. The reciprocal 'shadow' projection has intervened in the conflicting relationship between Yi and Won. In concern to the argument for the suicidal death of Yi Sun-sin, the author found no evidence supporting such an argument, No trace of latent suicidal wish was found in his dreams. For Yi Sun-sin, the determination of the life and death depends on Heaven. 32 dreams from the diary and 3 from other historical references were reviewed and analyzed in the Jungian way. Symbols of anima, Self, and individuation process were found. His dream repeatedly suggests that Yi Sun-sin is an extraordinary man chosen by the divine man (神人). In the dream, Yi Sun-sin was a disciple of the divine man receiving instructions on various strategies, and he alone could see the great thing or events. The dream of a beautiful blue and red dragon, whom he was friendly touching, indicates Yi Sun-sin's eligibility for the kingship. Yi Sun-sin seemingly did not aware of this message of the unconscious. Perhaps he sensed something special but did not identify with 'the disciple of gods' and 'royal dragon' in his dream. His modest attitude toward the dream has prevented him from falling into ego inflation. There were warning signals in two dreams that suggested disorders in the dreamer's instinctive feminine drive. Spirits of the dead father and brothers appear in the dream, giving advice or mourning for the death of Sun-sin's mother. Though Yi Sun-sin was a genuine Confucian gentleman, a dream revealed his unconscious drive to destroy the Confucian authoritative 'Persona' by trampling down the cylindrical traditional Korean hat. To the dreams of synchronicity phenomena Yi Sun-sin immediately solves the problem in concrete reality. He understood dreams as valuable messages from the superior entity, for example, the Confucian Heaven (天) or Heaven's Decree (天命). Furthermore, the 'Heaven' presumably arranged for him the way to the national hero and imposed necessary trials upon him. Both his persecutors and advocates of him guided him in the way of a hero. Yi Sun-sin followed his destiny and completed the living myth of the hero. His mother, King Seon-jo, and prime minister Liu Seong Yong, all have contributed to embodying the myth of the hero. Yi Sun-sin died and became god, the divine healer of the nation.