• 대한치주과학회:학술대회논문집
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• 2003.11a
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• pp.122-123
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• 2003

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.278-283
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• 2017

Purpose: The aim of this study was to evaluate the interdental distances of anterior, premolar, and molar teeth at the cementoenamel junction (CEJ) and 2 mm below the CEJ in healthy natural dentition with cone-beam computerized tomography (cone-beam CT) in order to provide valuable data for ideal implant positioning relative to mesiodistal bone dimensions. Materials and Methods: Two hundred patients who visited Dental Hospital, Wonkwang University, who had natural dentition with healthy interdental papillae, and who underwent cone-beam CT were selected. The cone-beam CT images were converted to digital imaging and communication in medicine (DICOM) files and reconstructed in three-dimensional images. To standardize the cone-beam CT images, head reorientation was performed. All of the measurements were determined on the reconstructed panoramic images by three professionally trained dentists. Results: At the CEJ, the mean maxillary interdental distances were 1.84 mm (anterior teeth), 2.07 mm (premolar), and 2.08 mm (molar), and the mean mandibular interproximal distances were 1.55 mm (anterior teeth), 2.20 mm (premolar), and 2.36 mm (molar). At 2mm below the CEJ, the mean maxillary interdental distances were 2.19 mm (anterior teeth), 2.51 mm (premolar), and 2.60 mm (molar), and the mean mandibular interproximal distances were 1.86 mm (anterior teeth), 2.53 mm (premolar), and 3.01 mm (molar). Conclusion: The interdental distances in the natural dentition were larger at the posterior teeth than at the anterior teeth and also at 2 mm below the CEJ level compared with at the CEJ level. The distances between mandibular incisors were the narrowest and the distances between mandibular molars were the widest in the entire dentition.

• 대한치주과학회:학술대회논문집
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• 2000.11a
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• pp.125-125
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• 2000

• 대한치주과학회:학술대회논문집
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• 2000.11a
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• pp.67-67
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• 2000

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.12-22
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• 1997

본 연구는 현재 국내에서 생산되는 주요 승용차의 운전석과 운전석 주변 제어장치간의 규 격이 한국 성인의 신체에 맞게 설계되었는지를 분석하고 평가하여 한국인의 신체에 적합한 승용차 내부설계의 개선안을 제시하고자 한다. 이를 위해 최근의 한국인 인체 측정 자료를 이용하여 운전자가 운전석에서 갖추어야 할 편안한 자세를 3차원 인체 모델링 도구인 SAFEWORK을 이용하여 모델링하였다. 이 모델링을 위해 본 연구에서는 사람과 환경과의 관계를 고정적인 인체 측정 데이터와 기능적인 인체 측정 데이터를 동시에 고려하여 삼차원으로 모델링한 다음 현재 국 내에 판매중인 소형, 준중형, 중형승용차 3종류의 규격차를 적용한 시트를 SAFEWORK으로 설계하였다. 한국인 인체 측정 데이터로 만들어진 마네킨을 설계된 각각의 시트에 앉혀 시트의 규격과, 운전석 주변의 제어장치간의 규격에 대한 적합성 여부를 판단한 결과, 운전석에서 accelerator pedal까지의 거리와 volume control 까지의 거리, 운전석의 깊이와 뒷좌석 폭 등 연구대상이 된 3종류의 내수용 승용차의 주요 규격이 한국 성인의 신체에 부적합하다는 결과가 나왔다. 이에 한국 성인의 인체 측정 데이터에 적합한 시트와 주변 제어장치간의 설계 규격을 제시하고자 한다.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.330-336
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• 2015

Purpose: This study evaluated the effect of loss of interproximal papilla, creating an undercut, on the accuracy of impression materials. Materials and methods: Two addition type silicone impression materials ($Extrude^{(R)}$ Speed Wash, $Imprint^{TM}$ II Quick Step Light Body) and one alginate impression material (Cavex Impressional) were used to make impressions of a maxillary master model simulating clinical conditions with or without interproximal papilla. Stone was poured in the impressions and working casts were fabricated. A total of 6 groups with 6 working casts in each group were scanned using 3-dimensional optical scanner. The accuracy of the impressions was assessed by measuring the dimensional changes (${\Delta}I$ (%)) of 6 distances on working casts compared to a master model with a 3-dimensional digitizing and inspection software. The data were analyzed by two-way ANOVA (P<.05). Results: Three of 6 distances showed statistically significant differences among the impression materials. Only 1 of 6 distances in alginate impression showed a statistically significant difference between casts with and without interproximal papilla (P=.047). Conclusion: The presence of undercut due to loss of interproximal papilla did not significantly influence the dimensional accuracy of addition type silicone and alginate impression materials.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.155-164
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• 2003

현재 국내에서는 교통사고 재현 방법이 노면 흔적물에 의존하여 이루어지고 있고, 노면 흔적물이 없는 경우 교통사고 재현은 불가능하게 된다. 이러한 단점을 보완하기 위해 외국에서는 충돌모델을 이용한 교통사고 재현프로그램을 활용하고 있는 추세이다. 현재 우리나라에서 가장 많이 사용하는 교통사고 재현 프로그램 PC-CRASH를 활용하기 위해서는 각 사고마다 알맞은 충돌특성 인자 값을 사용자가 직접 입력하여 사용하여야 하나, 이를 활용할 수 있는 활용자료가 부족한 실정이다. 본 연구는 국내에서 실제 발생된 교통사고 사례에 대해 교통사고 재현 프로그램인 PC-CRASH와 충돌에 영향을 미치는 충돌 인자들로 교통사고를 재현하였고, 차량의 최종위치간 거리와 자세에 어떠한 영향을 미치는가를 알아보았다. 또한 실제 역 해석을 하기 위해 차량의 최종위치와 자세만으로 각각의 사례에 적절한 인자값을 추정할 수 있는 회귀식을 구성하였고, 통계적으로 신뢰성을 검증하였다. 사고 재현에 필요한 주요 충돌인자들의 초기치 설정시 추정식을 이용할 경우, 사고 재현 프로그램 활용 시, 시간 단축 효과를 프로그램 내부에 있는 유전자 알고리즘의 반복횟수로 추정식의 통계적 검증을 하였다.

• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.535-546
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• 1996

The purpose of this study was to classify mandibular dental arch forms based on Raberin's method, and to compare Raberin's arch forms with that of the Korean's, and to designate arch form of bracket level according to distance between cusp tip and buccal surface of bracket level. The sample consisted of 159 mandibular dental casts showing normal occlusion which was taken from 62 males and 97 females of the Korean, aging from 13 to 25 years. The model was taken by X-ray. The landmarks were cusp points which expressed the mandibular dental arch line of cusp tips and buccal points which were measured from cusp tips to buccal surfaces of bracket level. The landmarks on the film were digitized, and measurements and statistics were performed. The results were as follows; 1. The models were classified as type 1, type 2, type 3, type 4 and type 5 by the author, and polynomial functions of the six degree and R-square values were calculated using statistical method, and each calculated equations explained each group with the least R-square value of 0.97, and each arch forms' were plotted. 2. The distribution of type 1 was $17.6\%$, type 2 $20.8\%$, type 3 $20.8\%$, type 4 $16.3\%$ and type 5 $24.5\%$. 3. The Korean arch form was characterized by larger width, smaller height compared to the French arch form. 4. The designated arch form of bracket level, viz the distance between cusp point and buccal point was calculated. The distance between cusp point and buccal point of incisor was 1mm, canine 1.9mm, first premolar 2.5mm, second premolar 2.6mm, first molar 2.7mm and second molar 2.7mm.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.97-103
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• 2018

Purpose: The aim of this study was to evaluate the Bonwill triangle of Korean using the cone beam computerized tomography (Cone-beam CT). Materials and Methods: 120 Koreans (60 males and 60 females) who visited Daejeon Dental College Hospital of Wonkwang University and who underwent the Cone-beam CT were selected. The Cone-beam CT images were analysed with Invivo 5.1 (Anatomage, San Jose, USA). After reorientation of axis, the intercondylar distance was measured by clicking both middle points of condyle. And the condyle-incisor distance was measured by clicking the middle point of condyle and contact point of the mandibular central incisor's incisal edge. The collected data were analysed using the SPSS Version 23.0 (IBM Inc., Armonk, USA) and statistical significance was verified by gender using independent t-test. Results: The mean intercondylar distance of Korean was 105.9 mm, and the male (108.3 mm) was statistically significantly larger than the female (103.4 mm). The mean condyle-incisor distance of Korean was 105.2 mm, and the male (108.1 mm) was statistically significantly larger than the female (102.3 mm). Conclusion: The mean intercondylar distance of Korean in this study was 105.9 mm that was smaller than well-known 110 mm of Caucasian and the male was statistically significantly larger than the female. Within the limitations of this study, it would be necessary to use the articulator which can adjust the intercondylar distance according to the individual for prosthodontic treatment of Korean.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.517-524
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• 1995

This study was conducted to investigate the characteristics of the road alignment, correlations among evaluation factors of the alingment, and the relationships between the evaluation factors and terrain factors for the forest road of five National Forest Offices. The results were as follows : 1. The elongation coefficients(${\eta}$) of forest road in Kangnung and Wonju National Forest Office were ranged 0.3~0.5, and those of Andong, Namwon, and Kongju National Forest Offices were ranged 0.2~0.3 in straight line of 100m, 200m, and 300m. 2. Three different types of plane alignment were identified for Kangnung and Wonju National Forest Offices, Namwon and Kongju National Forest Offices, Andong National Forest Office. However, longitudinal alignment for five National Forest Offices tended to be similar conditions. 3. Low correlation coefficients were calculated in the relation between elongation coefficients(${\eta}$) and evaluation factors of plane alignment(curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$)) for three straight lines. On the contrary, high correlation coefficients were obtained among the relations of curve length ratio(%), sum of inverse number of each curve radius(m/km), and sum of each intersection angle($^{\circ}/km$). 4. Slope(%) were closely correlated with plane alignment, and so were the relationships between frequency of valleys and streams(No./km) and elongation coefficients(${\eta}$) of forest road.