• 대한치과의사협회지
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• 제21권5호통권168호
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• pp.395-402
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• 1983

The purpose of this study was to apply the etched metal ceramometal retainer using a composite resin and acid-etch procedure with minimal tooth reduction of abutments for the replacement of one missing anterior or posterior tooth. Author obtained the following conclusions. 1. conservation of tooth structure and minimal chair time and patient expense were the primary advantages of etched metal retainer. 2. This fixed partial denture permitted good esthetic results. 3. This retainer was successfully applied for the replacement of one missing anterior or posterior tooth. 4. Proper retainer etching ws an important procedure. 5. Etched castings could be applied to periodontal splinting and post orthodontic fixation.

• 동력기계공학회지
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• 제14권3호
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• pp.64-70
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• 2010

In this study, designing of precise linear transferring device which can be applied to industrial machine and robot industry has been introduced. The direction of power flow and output feature are similar to current Rack-Pinion type. However, unlimited length extensity via rack modulizing, and securing high velocity transportation have been realized by applying Pin-Pinion Gear type at the operation part. The analysis has been calculated to obtain the Pin-Pinion Gear's optimized tooth profile. As a result of research, it is impossible to control precisely even overlap at the teeth of involute and sprocket. Because they have peculiar gearing structure. Therefore, modified cycloid tooth has been proposed to perform high velocity, precise control without backlash.

• 한국정밀공학회지
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• 제22권10호
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• pp.210-217
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• 2005

This study examined the effect of cancellous bone microstructure on stress distribution within a premolar tooth and a dental implant against mastication force by the micro-finite element method (FEM). The mandibular specimen including a premolar was obtained from a cadaver and scanned with micro-CT to obtain CT images. FE models were reconstructed from CT images at mid-sagittal plane of the tooth. Six models were generated and analyzed for different structure and density in cancellous bone. Stress distributions fur each implant (or tooth) and the surrounding bone were compared. The study indicated that the microstructure of cancellous bone should be considered in finite element analysis to produce reasonable results and thus implant systems with high success rate.

• 치과방사선
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• 제7권1호
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• pp.27-30
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• 1977

To insure accuracy in dental roentgenographs, it is important that the patient's head position and angulation of the x-ray tube. In 1907 Cieszynski applied the rule of isometry to dental radiography and established that in the production of an accurate image of a tooth, the central ray must be porjected perpendicularly to a plane bisecting angle formed by the longitudinal axis of the tooth and the film plane. Proper exposure of the film is a part of the production of a good dental radiograph, and correct processing also makes an essential contribution to the quality of the radiograph. The author analysed the failure of exposure and processing results, and recommended followings. 1. The patient head must be positioned that occlusal plane are parallel with the horizontal floor. 2. Central ray must be projected to the objective tooth and supporting structure and projected as perpendicularly to tooth axis and film surface as possible. 3. In processing, the temperature of the solution and the processing time must be correct.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 추계종합학술대회
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• pp.231-234
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• 2002

본 논문에서는 생체인식기술(biometrics)의 한 유형인 치아의 패턴과 특징을 기반으로 하여 사람을 구분하여 출입을 통제할 수 있는 시스템에 대해서 고찰하였다. 본 논문에서는 고정적이며, 구조가 간단한 치아를 첨단영상 이해기법을 이용하여 치아인식을 이용한 출입통제 시스템에 대한 연구개발을 목적으로 얼굴 인식의 전단계 또는 보조 수단으로 활용하여 큰 효과를 거둘 수 있을 것으로 보고 있다.

• 한국패류학회지
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• 제31권1호
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• pp.49-59
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• 2015

우리나라를 비롯한 아시아, 유럽, 호주 등에서 채집한 쇠우렁이 과 패류 8종 (Bithynia striatula, B. tentaculata, B. siamensis, B. leachi, B. kiusiuensis, B. misella, Bithynia sp., Gabbia australis) 을 대상으로 주사전자현미경 (SEM) 을 이용하여 치설을 관찰한 바 다음과 같은 결과를 얻었다. 치설열의 수는 B. siamensis와 B. leachi의 경우 60-70개로 다른 종들의 치설열의 수 40-50개보다 많았다. 관찰한 8종의 패류의 치설 구조는 좌우대칭으로 한 치설열에 7개의 치아가 있었다. 즉 1개의 중치를 중심으로 좌우에 각각 1개의 측치와 2개의 외연치가 분포하였다. 따라서 기본 치설식은 2:1:1:1:2로 표시할 수 있었다. 소첨두의 수와 모양은 개체별, 종별로 차이가 있었으며 중치에만 기저돌기가 분포하였다. 중치의 중앙돌기의 구조는 B. striatula, B. tentaculata, B. siamensis 및 Bithynia sp.의 구조가 다른 종들과 차이가 있었다.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.64-72
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• 1994

Zinc Phosphate Cement hand been used for about more than 100 years in luting of cast gold inlay. But many scientists had been trying to develop the new form of luting agent because the ZPC hand shown the lack of adhesiveness on the tooth structure and the toxicity to the pulp tissue. Recently many researches about the surface treatment of the cast body are being done to increase the adhesion of cement to it. The conventional Class I gold inlays were fabricated in the 20 permanent molars. After the internal surface of the cast body was sandblasted with $Al_2O_3$ particles and was tin-plated, the inlays were cemented with adhesive cement [G I cement and resin cement(Super-Bond & $Panavia_{EX}$)] and the evaluation on the adhesion pattern, adhesive strength and the fracture pattern of the adhesive cast gold inlay was compared to that of the cast gold inlay cemented conventionally with ZPC. The results were as follows : 1. The surface roughness of the cast body was increased significantly after sandblasting with the $Al_2O_3$ particles and the tin oxide layer, which was consisted of round particles, came into being. 2. The bond strength was in the order of Super-Bond, ZPC, Fuji I, $Panavia_{EX}$ group. The group cemented with Super-Bond showed statistically greater strength than the other groups(p<0.05). 3. The group cemented with ZPC was fallen apart by principal adhesion failure and that with Fuji I was by complete adhesion failure. But the group with Super-Bond showed pricncipal cohesive failure pattern and in the group with $Panavia_{EX}$, complete cohesive fracture pattern was shown and small protion of tooth structure was fractured out with cast body and the fractured surface showed the figure just as the enamel prism. 4. Various gaps were shown at the pulpal side regardless of little gap at the side walls of the cavity in all groups. Only the Super-Bond was attached to the tooth structure and the other cements were detached from both the tooth and the cast body.

• Design & Manufacturing
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• 제8권1호
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• pp.40-44
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• 2014

As a rotating machine element, plastic gears are more and more widely used in such as industrial machine element, since plastic gear is lighter, higher wear-resistance, and higher vibration absorbing ability than metal gears. When operating plastic parts, tooth breakage and fatigue life shortened due to increasing number of applying load and tooth flank temperature rising, such that accuracy of plastic gears is divided from allowable range to cause vibration and noise. On this study, a internal plastic gears are developed which improved the filling balance molding process by a new injection mold structure. The new mold structure called HR3P(hot runner type 3plate mold). As the result from this studies, we obtained a very accurate roundness internal gears by using design of experiment.

• 열처리공학회지
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• 제13권4호
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• pp.217-223
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• 2000

The boronizing effects of STD 61 steel have been studied on the micro structure and hardness. The STD 61 Steel was soaked in molten salt, consisted of KCl, $BaCl_2$, NaF, $B_2O_3$, FeB, and Ce, at various temperatures and times. The boronizing conditions for the peak hardness were the temperature range of $900^{\circ}C$ to $950^{\circ}C$ for 5 hr and that of $1000^{\circ}C$ for 3 hr, respectively. Four boride layers such as FeB, $Fe_2B$, ${\alpha}$ and matrix layer surface were observed from the microscopic surface examination. The thickness of boride layer was increased by increasing the boronizing time and the temperature. The structure of boride layer was tooth shape.

• 한국금형공학회:학술대회논문집
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• 한국금형공학회 2008년도 하계 학술대회
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• pp.129-133
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• 2008

As a rotating machine element, plastic gears are more and more widely used in such as industrial machine element, since plastic gear is lighter, higher wear-resistance, and higher vibration absorbing ability than metal gears. When operating plastic parts, tooth breakage and fatigue life shortened due to increasing number of applying load and tooth flank temperature rising, such that accuracy of plastic gears is divided from allowable range to cause vibration and noise. On this study, a internal plastic gears are developed which improved the filling balance molding process by a new injection mold structure. The new mold structure called HR3P(hot runner type 3plate mold). As the result from this studies, we obtained a very accurate roundness internal gears by using design of experiment.