• 대한소아치과학회지
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• 제32권1호
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• pp.132-135
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• 2005

본 연구의 목적은 유전치 심미수복의 새로운 방법으로 glass fiber를 이용한 강화형 strip crown의 사용을 제시하고자 하는 것이다. Strip crown의 제작을 위하여 celluloid crown form(3M, USA)과 복합레진은 Z100(P shade, 3M, USA)을, 유동성 복합레진은 Aeliteflo(Bisco Inc., USA)를 사용하였다. 상아질 결합제는 Clearfil SE Bond(Kuraray Medical Inc., Japan)를 사용하였고 강화를 위하여 그물형 glass fiber(TESCERA Fiber Mesh, Bisco Inc, USA)를 사용하였다. 적절한 크기의 celluloid crown form을 성형하여 삭제된 치아에 시적한 후 레진 접착제와 유동성 복합레진으로 처리한 그물형 glass fiber를 설측 내면에 삽입하고 광중합하였다. 잔여 공간에 복합레진을 채우고 치아에 끼운 다음 광중합하였다. 복합레진의 심미성은 유지하면서 glass fiber로부터 기계적 장점을 얻을 수 있을 것으로 사료된다. 새로운 강화형 strip crown의 물성에 대한 후속연구가 필요하다.

• 대한기계학회논문집
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• 제16권8호
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• pp.1451-1457
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• 1992

본 연구에서는 작업롤의 온도분포를 정상 상태에서 롤의 길이 방향만을 고려 한 경우에 대하여 구한 다음 Fouries 급수로 전개하여 이 온도분포에 따른 작업롤의 축대칭 3차원 열-탄성문제를 해석함으로서 롤의 크라운 양과 열응력을 구하여 이 결과 를 유한요소법에 의한 결과와 비교 검토 하였다.

• 대한소아치과학회지
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• 제44권3호
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• pp.306-316
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• 2017

이 연구는 유전치와 그 심미 수복에 사용되는 전장관의 어린이 음료수에 대한 색조 안정성을 평가하였다. 우식 및 변색 없이 자연 탈락된 20개의 상악 우측 유중절치와 상악 우측 유중절치 모양의 resin strip crown 40개 및 Nu-smile zirconia crown 20개를 대상으로 하였다. 복합 레진의 연마 여부에 따른 색조 안정성을 비교하기 위해 40개의 resin strip crown 중 20개는 $Sof-lex^{TM}$ Contouring and Polishing Discs를 이용하여 연마하였다. 이 후 각각의 시편을 5개씩 나누어 증류수, 콜라, 포도주스, 젤리주스에 6일간 담갔다. 그 결과 네 음료수 군에서 모든 시편의 색조 변화가 있었으며, 연마한 resin strip crown은 연마하지 않은 군에 비해 색조 변화가 컸고 콜라, 포도주스, 젤리주스에서 통계적으로 유의하였다(p < 0.05). Zirconia crown의 경우 포도주스와 콜라에서의 색조 변화 값은 통계적으로 유의하지 않았으나 젤리주스와 나머지 두 음료수 사이에서는 유의하였다(p < 0.05). 따라서 소아 유전치 수복에 사용하는 수복재료들도 어린이 음료수에 노출될 경우 색조 변화가 있을 수 있으므로 어린이 음료수에 대한 식이 조절이 필요하다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2002년도 춘계학술대회 논문집
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• pp.39-43
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• 2002

A new model for heat transfer and thermal deformation analysis according to strip mm in coiling process has been proposed. Finite difference analyses for heat transfer of cold rolled coil have been carried out under various coiling tensions and strip crown using the equivalent thermal conductivity for the radial direction of cold rolled coil which is a function of strip thickness, surface characteristics and compressive pressure. The compressive pressure is calculated from a equation expressed as a function of hoop stress and coil tension considering strip mm obtained by experiment. Finite element method for thermal deformation of cold rolled coil has been performed to investigate the effects of the strip crown, the coil tension and temperature. From these analyses, it is found that the axial inhomogeneity of thermal deformation is increased as the strip crown, compressive pressure, and temperature drop in cold coiled strip increase.

• 소성∙가공
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• 제14권1호
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• pp.43-48
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• 2005

The production of metal strip with uniform thickness and flatness are two important problems associated thin strip rolling. The thickness and flatness of strip are affected by the flattening of contact surface between strip and roll, the elastic recovery and the bending of roll. Especially, the flatness of the strip is greatly affected by bending deflection of roll. The roll must be designed considered the elastic deformation of roll. This study describes the measurement of thickness and flatness of strip and shows the crown roll for producing flat strip. But it is difficult to produce the crown roller. The cross rolling that is a simple method which can produce the flat strip is introduced and it is found the optimal cross angle for improvement of flatness of plate. These problems are solved by the MARC code on the basis of elastic-plastic material and the updated Lagrangian formulation.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.184-187
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• 2003

The simulation program is developed to get the target strip crown of high strength steel in the continuous hot strip rolling. The developed program consists of several sub-program, which contains work roll shifting pattern, roll wear profile, roll thermal expanded profile and strip profile. Also, the variation of strip profile is investigated according to roll deflection and flattening. The results are compared with the values observed from the actual hot rolling of high strength steel. And effect of bender force on the strip profile is studied. The strip crown is shown to decrease with increasing bender force.

• 한국정밀공학회지
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• 제19권11호
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• pp.200-210
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• 2002

In twin roll strip casting process, coupled analyses of heat transfer and deformation for the cast roll are carried out by using the finite element program MARC to examine the thermal crown. Shrink fit effect and plastic deformation are considered. The results shows that the thermal crown is greatly influenced by shrink ft and that the thermal crown for POSCO Pilot Caster 2 Copper Roll has “M” shape. The effects of several factors on thermal crown are also investigated. The amount of thermal crown increases as heat flux, casting speed, steeve thickness and casting roll width increase and decreases as the casting roll diameter increases.

• 대한소아치과학회지
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• 제25권3호
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• pp.627-634
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• 1998

Children who have severely destructive anterior primary dentition, as in nursing-bottle caries, in trauma, in rampant caries and in developmental defects, present the dentist with one of the most perplexing situations in dentistry. Especially, children with managed behavor difficultly is very severly situations. This paper reported a new technique for the utilization of resin post and strip crown to indirect methods on severely destructive primary anterior teeth. We name it "indirect short resin post crown" in this paper. Indirect technique be considered to be a simple, a retentive, intensive, color-stable and esthetic restoration.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 춘계학술대회 논문집
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• pp.229-232
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• 2007

In hot strip rolling, the work roll profile is one of the main factors in predicting and correcting the strip profile. Various studies concerning the wear profile and the thermal crown of work roll have been performed, and the results of these studies have shown that the work roll profile must be predicted accurately so as to efficiently control the strip qualities such as thickness, crown, flatness, and camber. Therefore, a precise prediction model of roll profile is called for in a perfect shape control system. In this paper, a genetic algorithm was applied to improve on the roll profile prediction model in hot strip rolling. In this approach, the optimal design problem is formulated on the basis of a numerical model so as to cover the diverse design variables and objective functions. A genetic algorithm was adopted for conducting design iteration for optimization to determine the coefficient of the numerical model for minimization of errors in the result of the calculated value and the measured data. A comparative analysis showed a satisfactory conformity between them..

• 소성∙가공
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• 제16권4호
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• pp.250-253
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• 2007

In hot strip rolling, the work roll profile is one of the main factors in predicting and correcting the strip profile. Various studies concerning the wear profile and the thermal crown of work roll have been performed, and the results of these studies have shown that the work roll profile must be predicted accurately so as to efficiently control the strip qualities such as thickness, crown, flatness, and camber. Therefore, a precise prediction model of roll profile is called for in a perfect shape control system. In this paper, a genetic algorithm was applied to improve on the roll profile prediction model in hot strip rolling. In this approach, the optimal design problem is formulated on the basis of a numerical model so as to cover the diverse design variables and objective functions. A genetic algorithm was adopted for conducting design iteration for optimization to determine the coefficient of the numerical model for minimization of errors in the result of the calculated value and the measured data. A comparative analysis showed a satisfactory conformity between them.