단일 단계 접착제의 변연 미세누출

조영곤,정진호,기영재,최희영,진철희,유상훈,김종욱,박병철 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

This study evaluated the marginal microleakage of five single step adhesives. Class V cavity preparations with occlusal margins in enamel and gingival margins in dentin were prepared on both buccal and lingual surfaces of extracted human molar teeth. Prepared teeth were randomly divided into five groups and restored using one of the single step adhesives and composite resins: Prompt L-Pop/Filtek Z-250 (Group 1), AQ Bond/Metafil CX (Group 2), One-Up Bond F/Palfique Toughwell (Group 3), Futurabond/Admira (Group 4), Xeno III/Spectrum TPH (Group 5). The restored teeth were thermocycled. Microleakage was assessed by dye penetration using 2% methylene blue dye solution. The teeth were bisected buccolingually and evaluated for microleakage under steromicroscope. The data were statistically analysed by Kruskal-Wallis test and Mann-Whitney tests. The results of this study were as follows; 1. Microleakage of enamel margins in group 3 was statistically higher than that in groups 1, 2, 4, 5 (p < 0.05) 2. Microleakage of dentin margins in group 1 was statistically higher than that in groups 2, 5, and that in group 3 was statistically higher than that in groups 2, 4, 5 (p < 0.05). 3. Dentin marginal microleakage was higher than enamel marginal microleakage in all experimental groups. In conclusion, Prompt L-Pop showed the least leakage at enamel margin, and AQ Bond showed at dentin margin in this study. Marginal miroleakage in dentin was higher than that in enamel.

자가 산부식 프라이머의 적용시간이 상아질의 미세인장 결합강도에 미치는 영향

조영곤,이영곤,김종욱,박병철,김종진,최희영,진철희,유상훈 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.5

This study evaluated the influence of application time of self-etching primers on microtensile bond strength (μTBS) to dentin using three self-etching primer adhesive systems. Dentin surfaces were exposed from forty-eight human molars. They were conditioned with three self-etching primers (Clearfil SE Bond [SE], Unifil Bond [UF], Tyrian SPE + One Step Plus [TY]) and different primining times (10s, 20s, 30s and 40s). Composite resins were bonded to dentin surfaces and specimens were made. μTBS was tested and statistically compared using by one-way ANOVA and Tukey's Test. The results of this study presented that priming time for 10s in SE and UF groups and for 30s and 40s in TY group was highly decreased μTBS to dentin.

상아질에 적용된 재 습윤제가 미세인장 결합강도에 미치는 영향

강희영,조영곤,김종욱,박병철,유상훈,진철희,최희영,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.2

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength (μTBS). Human molars were sectioned to expose the superficial dentin surfaces. Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (0)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D) , blot dry (BD) or dry for 15s, and rewet with different rewetting agents[distil1ed water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)]for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with 1mm^(2) cross sectional area and the μTBS was determined by EZ test. In the S group, the mean μTBS of GD, AP and BD group was significantly higher than that of DW and D group (p < 0.05). In the 0 group, the mean μTBS of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05). The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.

복합레진의 지연충전이 미세인장 결합강도에 미치는 영향

박현식,조영곤,박병철,김종욱,최희영,김종진,진철희,유상훈,기영재 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this study was to evaluate the effect of immediate or delayed composite resin filling on dentinal microtensile bond strength (μTBS) after applied the adhesive. The coronal dentin of human third molars was exposed. Single-Bond or One-Step was applied on the dentin surfaces, and composite resin were constructed immediately (group 1) or 5 min., 10 min., 15 min., 20 min. and 30 min. (groups 2-6) after an adhesive was applied. The specimens were sectioned and made bar-shaped. Each surface area of them was about l ㎟. The RBS test was performed by EZ test. The results were analysed by One-way ANOVA and Tukey's test at 95 % significance level. The results suggested that the μTBS of Single-Bond to dentin was decreased when the composite resin was constructed 20 min. and 30 min. after Single-Bond was applied. But the μTBS of One-Step was not affected by delayed composite resin filling.

법랑질 접착에 대한 습윤 효과

고근호,조영곤,진철희,유상훈,김종욱,박병철,기영재,최희영,김종진 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

This study evaluated the microleakage and interfacial gap between enamel and composite resin under the dry and wet condition of the enamel surface, V shaped class 5 cavities were prepared on the occlusal portion of extracted human molars. Samples were divided into three groups: D group (air dry for 10-15s), BD group (blot dry with moist cotton pellet), and DR group (air dry for 10-15s and rewet with Aqua-Prep F for 20s). Cavities were filled using Aelitefil composite resin after applied One-Step. Microleakage was tested by 2% methylene blue dye solution and the data were statistically analysed by Kruskal-Wallis test and Mann-Whitney test. Also Enamel-resin interface was observed under SEM. Group BD showed statistically lower microleakage than group D (p〈0.05). but there was no statistically significant difference between group BD and DR (p)0.05). At the enamel-resin interface, group D showed the gap of 2 ㎛ thickness, but group BD and DR showed close adaptation. In conclusion, the use of blot dry and rewetting agent (Aqua-Prep F) resulted in decreased microleakage and improved adhesion between enamel and resin when using One-Step.

[논문]직렬형 2배수 권선비 변압비를 이용한 HBML PWM 인버터

고희영,김철우 釜山大學校生産技術硏究所 2005 生産技術硏究所論文集 Vol.64 No.-

본 논문에서는 고조파를 저감하고 출력 파형을 개선하기 위하여 H-Bridge 인버터와 변압기 조합을 이용한 다중레벨 인버터를 구성함에 있어 변압기 출력 전압의 조합을 이용한 새로운 하이브리드형 멀티레벨 인버터를 제안한다. 제안한 다중 레벨 인버터는 THD을 저감하기 위해 변압기의 권션비가 1배,2배,4배인 3대를 사용하여 출력전압을 기존의 9 레벨에서 15 레벨로 증가 하였다. 또한 PWM 인버터 스위칭 패턴을 변경하여 스위칭 소자수를 10개에서 8개로 저감하고,변압기를 4개에서 3개로 저감할 수 있는 방법을 제안한다. 제안된 다중레벨 PWM 인버터의 전력회로 및 제어신호의 타당성을 입증하기 위해 프로토 타입 15레벨 언버터에 대하여 실험을 행하였다.

치아회분과 석고혼합제재 매식과 자가골 동시 이식후 치유과정에 관한 실험적 연구

김영균,김흥중,이상호,여환호,임성철,설인택,정재헌 大韓顎顔面成形再建外科學會 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.1

The purpose of this study was to evaluate the efficacy of adding autogenous bone to the toothash-plaster mixture in the healing process of bone. Full-thickness round osseous defects with the diameter of 20mm were made at the calvarial bone of adult dogs (n=19) bilaterally, which were thought to be critical size defect. The right defects were repaired with the toothash-plaster mixture plus autogenous bone (compressed volume 0.3cc) and the left defects with only toothash-plaster mixture. At 2-, 4-, 8-, 12- and 20- week after implantation, dogs were sacrificed and evaluated the osseous healing of bony defects clinically, radiographically, and microscopically. The results were as follows : 1. At the clinical observation, the wound healed very well without any problem except severe swelling in the early period after operation. Slight depression was recognized at the both sides when the portions of cranial defect were palpated. 2. There were statistically significant differences between toothash-plaster mixture groups and autogenous bone added groups at the same period, and among the groups in the bone density of the digital radiograms (P<0.001).There was a tendency that bone density was increasing with time. 3. In light microscopic examination, new bone formation was more active in the autogenous bone added groups than toothash-plaster mixture groups at the early period after mplantation but there is little difference at 20-week after implantation. 4. In fluorescent microscopic examination, the fluorescent band could be observed at the area of active bone formation and the band was more distinct in the autogenous bone added groups then toothash-plaster mixture groups. 5. In transmitted electron microscopic examination, organelles such as rER, Golgi complex and secretory granule and osteoblast were observed. In summary higher volume ratio of autogenous bone is needed to improve the bone healing in that there is little difference between toothash-plaster mixture group and autogenous bone added group at the 20-week after implantation in spite of new bone formation was more active in the autogenous bone added groups than toothash-plaster mixture groups at the early period after operation.

퍼지 제어기 소속함수의 추정을 위한 진화프로그래밍 이용에 관한 연구

김승철,장종승,강신출,임영도 東亞大學校 附設 情報通信硏究所 1996 情報通信硏究所論文誌 Vol.4 No.1

On this paper, the design of fuzzy adaptive controller using an evolution programming combining fuzzy controller to be very effectove in the optimization problem will be proposed. On a proposing control structure, the optimization takes uncertain plants optimized membership function using EP, and we want to take an adaptive controller in the plant as well be adapted control structure to initiate approximate membership function in fuzzy. We show that proposed controller have a good performance than general fuzzy controller through a computer simulation and the real-time control of DC serve motor.

스위치드 릴럭턴스 전동기의 속도제어에 관한 연구

김창현,권영안,김철우 부산대학교 1994 生産技術硏究所論文集 Vol.47 No.

Switched reluctance motor has several advantages as a variable speed motor. This paper studies a speed control of SRM with widely slotted opto interrupter. A low resolution of the position sensor is compensated through additional counters. The variable structure system with feedforward control and PI control of turn on angle and turn off angle is proposed as a control method. This control method is verified through the experiment in this paper. 스위치드 릴럭턴스 전동기(SRM)는 제작의 용이성, 구동회로의 안정성등 여러가지 장점으로 가변속 전동기로서 많은 주목을 받고 있다. 본 논문에서는 위치센서로서 광폭 광센서를 사용하는 SRM의 속도제어에 관하여 연구한다. 저 해상도의 위치신호는 카운터 보조회로를 부가하여 보상하였고, 속도제어방식으로는 점호각과 소호각을 피드포워드제어 또는 PI제어를 수행하는 가변구조 시스템으로써 응답속도 및 속도추종 성능이 양호하게 이루어지는 제어알고리즘을 제시하였다. 또한 본 연구에서 SRM 구동시스템을 제작하고 실험을 통하여 본 제어알고리즘의 우수성을 입증하였다.

고진공내의 데칸용매하에서 요오드화 iso-프로필이 니트로벤젠 및 톨루엔과의 착물형성에 관한 연구

김영철,김세경,임종완,구덕자 漢陽大學校 環境科學硏究所 1991 環境科學論文集 Vol.12 No.-

고진공내의 데칸용매하에서의 요오드화 iso-프로필의 용해도를 8, 15, 25℃에서 니트로벤젠과 톨루엔이 존재할 때와 존재하지 않을 때의 두 경우에 대하여 각각 측정하였다. 데칸용매내에 니트로벤젠과 톨루엔이 존재할 때 요오드화 iso-프로필의 용해도가 존재하지 않을 때 보다 더 크고, 톨루엔과 요오드화 iso-프로필과의 상호작용이 니트로벤젠과의 상호작용보다 더 강하게 작용한다는 것을 알 수 있었다. 그리고 니트로벤젠과 톨루엔이 데칸용매내에 존재할 때 요오드화 iso-프로필과 니트로벤젠 및 톨루엔이 각각 불안정한 Complex를 형성한다고 생각되어 이 Complex를 여러 경우의 비율로 가정하여 계산해 본 결과 1 : 1 Comples를 형성한다고 보는 경우의 평형상수 K값이 비교적 일정한 값을 나타내었다. 그러므로 1 : 1 Complex 즉 ??과 ??이 용매속에 형성됨을 알았다. 또한 이 Complex의 생성에 대한 엔탈피, 자유에너지 및 엔트로피의 변화도 산출하였다. The solubilities of iso-propyliodide in decane on high vacuum were measured at 8℃, 15℃ and 25℃ in the presence and absence of nitrobenzene and toluene. When nitrobenzene and toluene exist in system respectively, the solubilities of iso-propyliodide in the presence of nitrobenzene and toluene are greater than in the absence, and the interaction of iso-propyl iodide with toluene is stronger than with nitrobenzene. In the presence of nitrobenzene and toluene, it could be thought that iso-propyl iodide forms unstable complex with nitrobenzene and toluene. The complex was assumed in various ways and it was evaluated that the equilibrium constant K value was relatively constant under the assumption of 1 : 1 complex. Thus, 1 : 1 complexes, ??과 and ?? are formed in the solution. Also, the changes of enthalpy, free energy and entropy for the formation of the complex were calculated.