배달 미니 게임 개발:"최고의 웨이터를 꿈꾸며"

김정훈,정한교,김영옥,김중곤,박정윤,윤진성,김경식 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

본 미니 게임은 웨이터라는 직업을 모티브로 하여서 남녀노소 누구나 재미를 느낌과 동시에 기억력 향상시켜 주는 게임제작이라는 목적아래 제작되었다.본 논문에서는 이 게임의 제작과정을 기술하고자 한다.이 게임은 제3회 AGC(한국 아마추어 게임제작 공모전)에서 우수 작으로 선정되었다.

국산화 개발한 치과용 저금합금의 시효경화 거동

김교한,권오원,김형일 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.1

To define the optimum heat treatment temperature and time of the developed three types of low karat gold alloys, hardness test, DTA and x-ray diffraction methods were used. The results were as follows. *The optimum temperature of heat treatment was at 400℃ in K-Ⅰ, K-Ⅱ and K-Ⅲ alloys. *The proper time of age-hardening was 10 minute in K-Ⅰ alloy, and 10-30-minutes in K-Ⅱ alloys. *The stable phases of three types of low karat gold alloys were Ag-rich α₁ phase, Cu-rich α₂ phase and AuCuⅠ phase in case of K-Ⅰ alloy, and α1 phase and AuCuⅠ phase were coexisted in K-Ⅱ and K-Ⅲ alloy. *The cause of the decrease of hardness by overageing was the α₁ phase and AuCu Ⅰ phase, which were precipitated in the grain boundary.

수술의 함정 : 중심성 신경세포종 2례 2 Cases of Central Neurocytoma

김범태,주교성,장채칠,신원한,최순관,변박장 대한신경외과학회 1999 Journal of Korean neurosurgical society Vol.28 No.3

Sandblast 처리한 상아질면의 접착에 관한 연구

김교한,나환욱,황성욱 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.1

Dentin adhesion was studied on sandblasted dentin with 4-META/MMA-TBB resin. The effect of change of air pressure, with or without pretreatment and primer on tensile bond strength, was mainly investigated. In the effect of air pressure at sandblast treatment, the higher pressure showed the increase of tensile bond strength. The pretreatment with 10-3 sloution after sandblast treatment increased tensile bond strength in the almost conditions. Application of primer also increased the tensile bond strength, confirmed the effect of primer application after sandblast treatment. Alumina particle was not found on the dentin surface in the SEM and EDAX examination.

치과주조용 저카라트 금합금의 시효경화

김형일,김종렬,안호경,장명익,설효정,김교한 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.2

The age-hardening behavior of a commercial dental casting low-carat gold alloy was investigated by means of differential thermal analysis, hardness test, optical microscopic observation and X-ray diffraction study. The following results were obtained. 1. By the isothermal aging of this alloy at 300∼400℃, the hardness increased markedly at the initial stage and continued to increased gradually for the time, and then decreased dractically after longer aging time. 2. The hardening was attributed to the formation of the metastable AuCu I' ordered phase from the α matrix. 3. The overaging with softening was attributed to the precipitation of the fine lamellar structure which was composed of the Ag-rich α1 and AuCu I ordered phases.

치과용 Au-Ag-Cu-Pd 합금의 시효경화특성

김형일,김영근,장명익,김교한 대한치과기재학회 1997 대한치과재료학회지 Vol.24 No.1

The relationship between the isothermal age-hardening behavior and the phase transformation process in a dental casting Au-Ag-Cu-Pd alloy was investigated by means of hardness test, X-ray diffraction study. 1. The isothermal age-hardening behavior in the 350∼450℃ temperature range showed a similar tendency in the changes. However, the initial hardening was faster and the maximum hardness was higher and the overaging with softening was slower on aging at the lower temperature. 2. By the isothermal aging at 350∼450℃, the metastable Ag-rica α₁’and AuCu Ⅰ’orderd phases were formed from the supersaturated α phase prior to the final formation of the equilibrium Ag-rich α₁’and AuCu Ⅰordered phases. 3. By aging at 450℃, the age-hardening was attributed to the lattice strains of the parent phases resulting from the transformation of the αphase resulting from the transformation to the metastable phases. The X-ray diffraction peaks of the αphase showed a distinct shift toward both the high and low diffraction angles during transformation.

TiN Ion-Plating이 교정용 브라켓의 접착강도에 미치는 영향

김석용,권오원,김교한 대한치과교정학회 1997 대한치과교정학회지 Vol.27 No.1

TiN ion-plating이 교정용 브라켓의 접착강도에 미치는 영향을 알아보기 위하여 세 종류의 서로 다른 기저면형태를 가지는 스테인레스 스틸제의 브라켓을 선택하고, TiN ion-plating 된 브라켓과 ion-plating 되지 않은 브라켓을 치아에 접착시켰을 때 초기 및 장기접착강도, 접착계면의 주사전자현미경 관찰, 파단면의 주사전자현미경 관찰을 비교 분석하여 다음과 같은 결론을 얻었다. · TiN ion-plating을 하지 않은 경우 24시간 후의 접착강도는 Micro-Loc형이 5.89±1.77MPa, Foil Mesh형이 4.27±1.12MPa, Undercut형이 2.64±0.58MPa로 Micro-Loc형이 가장 높았고, 그 다음이 Foil Mesh형 그리고 Undercut형의 순으로 나타났다(P<0.05). · TiN ion-plating시 24시간 후의 접착강도는 Micro-Loc형이 6.26±1.51 MPa, Foil Mesh형이 7.45±2.01MPa, Undercut형이 2.93±0.84MPa로 ion-plating 하지 않은 경우와 달리 Foil Mesh형이 Micro-Loc형보다 오히려 높게 나타났고, Undercut형이 역시 가장 낮은 접착강도를 나타내었다(P<0.05). Ion-plating 유무에 따른 24시간 후의 접착강도는 3가지형 모두에서 ion-plating시 증가하였으나 Foil Mesh형에서만 유의한 증가가 있었다(P<0.001). · 장기침적시 ion-plating의 유무에 관계없이 전반적으로 초기(1일)접착강도보다 증가하였으며 접착력의 안정성을 나타내었다. · 접착계면의 주사전자현미경 관찰 결과 브라켓 기저면의 형태나 ion-plating 유무에 관계 없이 레진이 브라켓 기저면으로 잘 퍼져 들어가 브라켓과 치아와의 사이에 견고한 접착면을 나타내었고, 장기침적의 경우도 같은 양상을 나타내었다. · 파단면의 주사전자현미경 관찰에서는 다양한 파괴양상이 나타났다. This study was conducted to see the effect of TiN ion-plating on the bond strength of orthodontic bracket. Three stainless-steel brackets with different base types were chosen; when TiN ion-plated brackets and non ion-plated brackets were bonded to the teeth, initial and long-term bond strength were measures. The observations of bonding surface and failure sites through the scanning electron microscope were analysed and compared. The summary of this study was as follows: · When TiN ion-plating was not applied, the Micro-Loc type was the highest in bond strength after 24 hours as 5.89±1.77MPa, followed by 4.27±1.12MPa for Foil Mesh type and 2.64±0.58MPa for Undercut type(P<0.05). ·Under TiN ion-plating, the bond strength after 24 hours showed: Micro-Loc type 6.26±1.51MPa, Foil Mesh type 7.46±2.01MPa, Undercut type 2.93±0.84MPa. Unlike in the case of non ion-plating, Foil Mesh type showed a higher strength than Micro-Loc type, with Undercut type still showing the lowest bond strength(P<0.05). The bond strength, after 24 hours, increased in case of ion-plated in all 3 types, but a significant increase was shown only in Foil Mesh type(P<0.001). · Under a long-term immersion, regardless of ion or non ion-plating, bond strength in general increased over the initial bond strength(one day), with more stability. · Through scanning electron microscopic observation of bonding surface, it was found that, regardless of the bracket base type or the application of ion-plating, the resin was thoroughly spreaded into bracket base to form a solid bonding surface between the bracket and the tooth. This was also true in case of a long-term immersion. · The scanning electron microscopic observation of failure sites revealed diverse failure patterns.

Sandblast 처리한 상아질면의 접착에 관한 연구

김교한,나환옥,황성욱 경북대학교 의학연구소 2000 경북대학교병원의학연구소논문집 Vol.4 No.1

Dentin adhesion was studied on sandblasted dentin with 4-MET/MMA-TBB resin. The effect of change of air pressure, with or without pretreatment and primer on tensile bond strength, was mainly investigated. In the effect of air pressure at sandblast treatment, the higher pressure showed the increase of tensile bond strength. The pretreatment with 10-3 solution after sandblast treatment increased tensile bond strength in the almost conditions. Application of primer also increased the tensile bond strength, confirmed the effect of primer application after sandblast treatment. Alumina particle was not found on the dentin surface in the SEM and EDAX examination.

치과 주조용 저금합금의 개발에 관한 연구

김교한,김형일 대한치과기재학회 1996 대한치과재료학회지 Vol.23 No.2

The purpose of this study was to develop the dental casting low carat gold alloys based upon Au-Ag-Cu ternary alloy. Three types of low carat gold alloy containing 46, 55 and 66wt. % of gold, content respectively, which were balanced with total amount of Au plus Ag of 74wt. %, were melted and casted to evaluate the mechanical properties, corrosion resistance, melting range and cytotoxicity. The obtained results were summarized follows : ·In mechanical properties, the type K-Ⅱalloys, which was increased in the amount of Pt component, showed 115MPa of yield strength, 400MPa of ultimate tensile strength and 150 of vicker's hardness value and these values are higher than those of K-Ⅰ, K-Ⅲ alloy of 30% in yield strength, 50% in ultimate tensile strength and 10% in hardness value. ·Age hardening effect was confirmed in all three alloys. ·Melting ranges of these alloys were in the range of 910-1050℃ ·Higher corrosion resistance was confirmed in the potential range of oral cavith. ·The cytotoxicity of alloys was evaluated by the cell growth and morphologic changes, Each alloy showed normal growth rate and cellular morphology.

Al-CuAl₂ 共晶合金의 一方向凝固組織과 機械的性質

金敎漢 영남이공대학 1982 論文集 Vol.11 No.-

The microstructure and mechanical properties of unidirectionally solidified Al-Cu eutectic alloys have been studied to research the effects of the growth rate. The temperature gradient is 80℃/cm and growth rate is controlled from 0.833mm/min to 18.75mm/min. The results obtained are as follows. 1) The interlamellar spacing is propertional to the growth rate and ;OR was 7.769x10^-5 mm^3/min. 2) The faster growth rate causes the higher mechanical strength. 3) Interrelationship between interlamellar spacing and hardness coincide with the Hall-Petch type equation.