• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.04a
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• pp.341-346
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• 1991

주물이 대형이고 난이한 자유곡면으로 이루어진 형상의 목형 제작에는 기준이 되는 각 단면의 도형 정보를 기초로 골격을 세워 그 틈새를 유연한 재료(모래, 시맨트, 스티로폴, 목재)로 메워 모형을 만드는 골격형 목형(Skeleton pattern)를 사용하여 왔다. 그러나 기준 단면사이의 형상보간 및 필요단면 정보는 틈새 메움시 현장 작업자의 수작업에 의존하여 작업되므로 제품 완성시 두께 분표불량등 정확한 주물을 제작할 수 없었다. 그러나 3차원 CAC 시스템의 발전과 더불어 자유곡면의 생성 및 조작이 손쉽게 이루어 짐으로써 정확한 형상 정의 및 처리가 가능하게 되어 기존 목형방법을 개선할수 있는 시스템을 개발하여, 프로펠라 목형을 대상으로하여 적용하였다.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.407-418
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• 2003

The purpose of this study is to analyze dentoalveolar compensation in normal occlusion samples previously classified into 9 skeletal types, and to provide clinically applicable diagnostic criteria for individual malocclusion patients. Cephalometric measurements of the 294 normal occlusion samples previously divided into 9 types were analyzed. The descriptive features of dentoalveolar variables were compared for the 9 types using analysis of variance, followed by post hoc multiple comparisons. In addition, the correlation between skeletal and dentoalveolar variables were analyzed. Discriminant analysis with a stepwise entry of variables was designed to find out several potential variables for use in skeletal typing. The dentoalveolar compensation pattern of the skeletal types varied, especially with regards to the variables that indicated the inclination of incisors and the occlusal plane. Stepwise variable selection identified four variables: AB-MP, SN-AB, PMA and ANB. Discriminant analysis assigned a classification accuracy of $87.8\%$ to the predictive model. On the basis of these results, this study could provide rudimentary information for the development of diagnostic criteria and treatment guidelines for individual skeletal types.

• The korean journal of orthodontics
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• v.33 no.3 s.98
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• pp.141-150
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• 2003

The purposes of this study were to classify the anteroposterior and vertical skeletal pattern of normal occlusion samples into specific types with factor and hierarchical cluster analysis, and to evaluate the range and limit of skeletal relationships that permit the establishment of normal occlusion via natural dentoalveolar compensation. Lateral cephalograms of 294 normal occlusion samples were measured, as selected from 15,836 persons through a community dental health survey who cooperated in record taking. Using a factor analysis, two factors representing anteroposterior and vertical skeletal relationships were extracted from 18 skeletal measurements. Then cluster analysis classified the skeletal patterns into nine types. The means and the standard deviations of 8 anteroposterior skeletal measurements and 10 vertical skeletal measurements were determined and comparisons of these measurements among the types were performed. The results obtained in this study showed that the range of normal occlusion included very diverse anteroposterior and vertical skeletal relationships.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.990-992
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• 2021

근골격계 질환 환자들은 정상인들에 비해 질환 부위의 관절 가동 범위(ROM, Range of Motion)가 제한되는 경향이 있다. 이러한 근골격계 질환 환자들의 관절 가동 범위 제한을 고려하지 않은 재활 운동 콘텐츠 서비스는 오히려 환자의 건강 상태를 악화시킬 수도 있으므로 주의해야 하는 서비스 요인이다. 본 논문에서는 근골격계 질환 환자의 제한적인 관절 가동 범위를 고려한 아바타 기반의 재활 운동 콘텐츠 서비스 기술을 제안한다. 이에 재활 운동의 모션 캡처 데이터로부터 아바타 재활 운동 콘텐츠로의 변환 기술과 근골격계 질환 환자의 관절 가동 범위 제한 정보를 적용한 아바타 기반 재활 운동 콘텐츠 재현 기술을 설계한다. 일련의 기술적 구성 요소를 고찰하고 설계함으로써 근골격계 질환 환자들의 서로 다른 관절 가동 범위를 반영한 맞춤형 재활 운동 콘텐츠 서비스가 안전하고 효과적인 재활을 지원할 수 있도록 한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.1
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• pp.21-27
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• 2013

In growing children it is frequently found that dental maturation is strongly influenced by the growth rate of maxilla or mandible. If there is evidence to prove this, it might be utilized as a criterion in the early diagnosis of skeletal malocclusion, even before the object's real skeletal features are yet revealed. The purpose of this study was to find out if the difference of dental maturation in over-grown mandible in children with skeletal Class III has any relationship with some skeletal features of mandible. 50 patients in Hellman dental age IIIA with normal occlusion and Class III malocclusion of mandibular over-growth type respectively were selected as study objects. The age estimation was performed on maxillary and mandibular teeth, eruption rate of the 2nd molars of each group have been measured on panoramic radiography, and the differences in dental age of the upper and lower jaw were analyzed under Demirijian's method. The results were as follows: The difference of dental age of maxillary and mandibular teeth between the two groups was 0.66 and 1.20 years respectively, with a higher difference in the experimental group (p < 0.05). The difference of eruption rate of the maxillary and mandibular second molar was not found between two group (p >0.05).

• The korean journal of orthodontics
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• v.32 no.2 s.91
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• pp.91-105
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• 2002

In general, orthodontists make problem lists and treatment plans based on norms of several cephalometric standards. But consideration of dentoalveolar compensation, which tends to maintain normal dental arch relationship in various skeletal jaw relationships, helps orthodontists make more individualized treatment objectives and plans. The purpose of this study was to classify skeletal patterns of normal occlusion samples by cluster analysis and to investigate the dentoalveolar compensation according to skeletal patterns. The subjects were consisted of 125 subjects who were normal occlusion samples at Seoul National University Dental Hospital, Department of Orthodontics. Lateral cephalograms in centric occlusion were traced and digitized. The skeletal patterns of normal occlusion samples were classified into three horizontal groups and three vertical groups by cluster analysis and ANOVA on the skeletal and dentoalveolar measurements among the groups were carried out. The results were as follows ; 1. Anteroposterior and vertical skeletal relationships of normal occlusion samples were very variable. 2. As the mandibular position was anterior to the maxilla, the maxillary incisors inclined more labially, the mandibular incisors more lingually, and the occlusal plane was flattened due to the anteroposterior dentoalveolar compensation. dentoalveolar height was decreased and upper posterior teeth was uprighted to the palatal plane and lower incisors and lower posterior teeth to the mandibular plane. 4. Lower incisors were more strongly associated with the dentoalveolar compensation than upper incisors according to the anteroposterior and vertical skeletal relationship.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.883-885
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• 2004

음함수 곡면은 부정형 물체의 모델링 성능이 탁월하여 다양한 골격요소가 사용된다. 골격요소의 모양이 다양할 수록 모델링 성능이 향상되는 반면 렌더링은 상대적으로 어려워진다. 따라서 본 논문에서는 다양한 골격요소를 사용하는 음함수 곡면을 interval method로 렌더링 하는 방법을 소개한다. 또한 정(point) 외에 복잡한 도형을 골격요소로써 사용할 때, interval method를 적용하는 경우 직면하게 되는 문제 해결 방법을 제안한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.303-304
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• 2022

근골격계 질환 재활환자들의 신체 능력을 평가하기 위한 주요 측정 도구로 관절 가동 범위(ROM: Range of Motion)가 사용된다. 본 논문에서는 근골격계 환자들의 재활운동을 통한 관절 가동 범위 정보를 시각적 이해하기 용이하도록 서비스하기 위하여 3차원 아바타를 이용한 관절 가동 범위 시각화 시스템을 제안한다. 제안하는 3차원 아바타를 이용한 관절 가동 범위 시각화 시스템은 근골격계 질환 재활환자들의 관절 가동 범위 데이터를 3차원 아바타의 대응하는 관절 작동 범위로 사상하고 다양한 시점으로 시각화하거나 애니메이션으로 재현함으로써 재활 수준의 변화를 직관적으로 제공할 수 있다.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.10-16
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• 2018

Purpose: The purpose of this study was to evaluate distalizing effects from the Pendulum appliance on vertical component of craniofacial structures. Materials and Methods: 20 Patients who visited for orthodontic treatments are assigned to two groups. Group I, SN-MP > 37 degrees are showing hyperdivergent pattern. Group II, 29 < SN-MP < 37 degrees are showing mesocephalic pattern. Each group are consisted of 10 people. Results and Conclusions: Differences between skeletal classifications result in significant differences at labioversion of lower incisors and distalized amount, which is larger at Group I (P <.05). Group II has only shown significant distalized molars (P < .05). Labioversion of lower incisors has not shown significant change. Skeletal anchorage-assisted Pendulum appliance doesn't deteriorate vertical component nor significantly improve.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.220-222
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• 2003

부정형 물체의 모양을 모델링 하는데 긴요하게 쓰이는 일반적인 음함수 곡면은 골격요소의 종류를 다양하게 선택함에 따라 모델링의 기능이 향상되는 반면 렌더링은 상대적으로 어려워진다. 본 논문에서는 점(point)과 함께 선분이나 원 등이 혼합된 골격 요소로 구성된 음함수 곡면의 렌더링을 위하여 interval method를 이용하는 광선 추적법을 제안한다. interval method는 점이 아닌 다른 모양의 골격 요소에 적용할 때는 난이도가 훨씬 증가하지만 광선과의 교차점을 구하는 등의 상대적으로 어려운 계산과정을 효과적으로 단순화 할 수 있다는 장점이 있다.