• 한국콘텐츠학회:학술대회논문집
• /
• 한국콘텐츠학회 2008년도 춘계 종합학술대회 논문집
• /
• pp.648-652
• /
• 2008

*.x 확장자는 3D 모델개발자와 3D프로그래머들이 프로그램을 보다 쉽게 개발하기 위해서 주로 사용된다. 오늘날에는 3D프로그래밍을 위한 하드웨어들의 성능이 많이 개선되었지만, 아직도 효율적인 애니메이션 생성을 위한 방법들에 관한 연구는 계속 진행되고 있다. 특히 3D 모델개발자들은 *.x 파일을 이용하여 골격애니메이션을 만들 때 한 부분의 에러가 다른 부분으로 전이되어 찌그러지는 현상이 나타날 수 있기 때문에 에러를 수정하는데 많은 시간이 필요로 하는 문제점을 내포하고 있다. 그래서 이와 같은 문제점을 해결하기 위해서 본 논문에서는 여러 개의 골격애니메이션을 블랜딩 할 수 있는 방법을 제안하였다. 이를 위해서 3D Max, Maya와 같은 애니메이션 블랜딩을 위한 프로그램이나 *.x 파일을 코딩하여 사용하고 있고, 골격 애니메이션을 합성하는 특수효과를 3D Max8.0을 사용하여 *.x 파일로 구현하였다.

• 과학교육연구지
• /
• 제42권2호
• /
• pp.95-105
• /
• 2018

이 연구의 목적은 생체 모방 기반 융합 학습 모델을 이용하여 골격근의 구조 및 수축 메커니즘에 대한 디지털 교과서를 개발하는 것이다. 골격근의 구조 및 수축 메커니즘 단원은 고등학교 생명과학I에 포함된 내용이다. 융합 학습 모델은 3D 모델링 및 프린팅을 포함하는 3단계의 생체 모방 기반 융합 학습(Exploration-Design-Implementation)으로 설계되었다. 개발된 디지털 교재는 8차시로 구성되어 있는데, 골격근 탐색, 스케치 앱과 3D 모델링을 이용한 골격근 모방 창의적 설계 2개 차시, 3D 프린팅을 이용하여 설계안의 융합적 구현, 근수축의 탐색, 스케치 앱과 3D 모델링을 이용한 근수축 모방 창의적 설계 2개 차시, 3D 프린팅을 이용하여 설계안의 융합적 구현 등으로 구성되었다. 각 차시는 대화 형 및 모바일 학습을 위해 갤러리 위젯, 미디어 위젯, 프레젠테이션 위젯, 스케치 위젯, 클라우드, 설문 위젯 및 평가 위젯의 컨텐츠를 포함하고 있다. 개발 된 디지털 교과서를 고등학생 20 명에게 투입한 결과 학생들의 생명과학 학습에 효과가 긍정적인 것으로 나타났다. 또한 이 연구에서 개발된 생체 모방 기반 융합 학습 디지털 교재는 학생들의 창의적 설계 및 구현 능력의 향상에서 효과적인 학습자료로 평가되었다. 이러한 결과를 볼 때 디지털 교재는 학생들의 흥미와 생명과학에 대한 자기주도적 학습에 유용한 자료임을 보여주었다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제38권
• /
• pp.13.1-13.12
• /
• 2016

Background: Mandibular motion tracking system (ManMoS) has been developed for orthognathic surgery. This article aimed to introduce the ManMoS and to examine the accuracy of this system. Methods: Skeletal and dental models are reconstructed in a virtual space from the DICOM data of three-dimensional computed tomography (3D-CT) recording and the STL data of 3D scanning, respectively. The ManMoS uniquely integrates the virtual dento-skeletal model with the real motion of the dental cast mounted on the simulator, using the reference splint. Positional change of the dental cast is tracked by using the 3D motion tracking equipment and reflects on the jaw position of the virtual model in real time, generating the mixed-reality surgical simulation. ManMoS was applied for two clinical cases having a facial asymmetry. In order to assess the accuracy of the ManMoS, the positional change of the lower dental arch was compared between the virtual and real models. Results: With the measurement data of the real lower dental cast as a reference, measurement error for the whole simulation system was less than 0.32 mm. In ManMoS, the skeletal and dental asymmetries were adequately diagnosed in three dimensions. Jaw repositioning was simulated with priority given to the skeletal correction rather than the occlusal correction. In two cases, facial asymmetry was successfully improved while a normal occlusal relationship was reconstructed. Positional change measured in the virtual model did not differ significantly from that in the real model. Conclusions: It was suggested that the accuracy of the ManMoS was good enough for a clinical use. This surgical simulation system appears to meet clinical demands well and is an important facilitator of communication between orthodontists and surgeons.

• 한국정밀공학회지
• /
• 제25권9호
• /
• pp.126-134
• /
• 2008

Kendo is one of the popular sports in modem life. Head, wrist and thrust attack are the fast skill to get a score on a match. Human muscle skeletal model was developed for biomechanical study. The human model was consists with 19 bone-skeleton and 122 muscles. Muscle number of upper limb, trunk and lower limb part are 28, 60, 34 respectively. Bone was modeled with 3D beam element and muscle was modeled with spar element. For upper limb muscle modelling, rectus abdominis, trapezius, deltoideus, biceps brachii, triceps brachii muscle and other main muscles were considered. Lower limb muscle was modeled with gastrocenemius, gluteus maximus, gluteus medius and related muscles. The biomechanical stress and strain analysis of human muscle was conducted by proposed human bone-muscle finite element analysis model under head, wrist and thrust attack for kendo training.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 추계학술대회 논문집
• /
• pp.965-966
• /
• 2010

• Archives of Plastic Surgery
• /
• 제50권3호
• /
• pp.254-263
• /
• 2023

Background The three-dimensional (3D) evaluation of skeletal stability after orthognathic surgery is a time-consuming and complex procedure. The complexity increases further when evaluating the surgery-first orthognathic approach (SFOA). Herein, we propose and validate a simple time-saving method of 3D analysis using a single software, demonstrating high accuracy and repeatability. Methods This retrospective cohort study included 12 patients with skeletal class 3 malocclusion who underwent bimaxillary surgery without any presurgical orthodontics. Computed tomography (CT)/cone-beam CT images of each patient were obtained at three different time points (preoperation [T0], immediately postoperation [T1], and 1 year after surgery [T2]) and reconstructed into 3D images. After automatic surface-based alignment of the three models based on the anterior cranial base, five easily located anatomical landmarks were defined to each model. A set of angular and linear measurements were automatically calculated and used to define the amount of movement (T1-T0) and the amount of relapse (T2-T1). To evaluate the reproducibility, two independent observers processed all the cases, One of them repeated the steps after 2 weeks to assess intraobserver variability. Intraclass correlation coefficients (ICCs) were calculated at a 95% confidence interval. Time required for evaluating each case was recorded. Results Both the intra- and interobserver variability showed high ICC values (more than 0.95) with low measurement variations (mean linear variations: 0.18 mm; mean angular variations: 0.25 degree). Time needed for the evaluation process ranged from 3 to 5 minutes. Conclusion This approach is time-saving, semiautomatic, and easy to learn and can be used to effectively evaluate stability after SFOA.

• 한국정밀공학회지
• /
• 제24권11호
• /
• pp.116-125
• /
• 2007

Human muscle skeletal model was developed for biomechanical study. The human model was consists with 19 bone-skeleton and 122 muscles. Muscle number of upper limb, trunk and lower limb part are 28, 60, 34 respectively. Bone was modeled with 3D beam element and muscle was modeled with spar element. For upper limb muscle modelling, rectus abdominis, trapezius, deltoideus, biceps brachii, triceps brachii muscle and other main muscles were considered. Lower limb muscle was modeled with gastrocenemius, gluteus maximus, gluteus medius and related muscles. The biomechanical stress and strain analysis of human was conducted by proposed finite element analysis model under Kumdo head hitting motion. In this study structural analysis has been performed in order to investigate the human body impact by Kumdo head hitting motion. As the results, the analytical displacement, stress and strain of human body are presented.

• 한국산업보건학회지
• /
• 제30권3호
• /
• pp.313-320
• /
• 2020

Objectives: The aim of this study is to evaluate the association between vibration exposure and skeletal muscle mass index through a single university health check-up. Methods: We used data from 134,067 male subjects who received a general health check-up or vibration exposure health check-up out of the 1,515,322 people who underwent medical check-up at a local university hospital from 2002 to 2018. Pearson correlation analysis was conducted for comparing the association between skeletal muscle mass index and demographic and hematological variables in both groups. Mixed linear model analysis after controlling demographic and hematological variables was used to analyze the differences in skeletal muscle mass index between groups at every visit over 10 years. Results: In the Pearson correlation test, the variables that showed different results when comparing the two groups were C-reactive protein (p=0.001) and glycated hemoglobin (p=0.002) in the vibration exposure group and erythrocyte sedimentation rate (p<0.001) and vitamin D (p<0.001) in the general group. After the adjustment of demographic and hematologic variables, the skeletal muscle mass index at every visit was markedly decreased in the vibration exposure group (p<0.001). Conclusions: In the vibration exposure group, the skeletal muscle mass index showed a tendency to decrease markedly over time compared to the general health check-up group, which showed that C-reactive protein and glycated hemoglobin would have an influence on skeletal muscle index in male workers exposed to vibration.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제29권3호
• /
• pp.163-168
• /
• 2003

Three-dimensional solid model has not been widely used in surgical prediction of orthognathic surgery because frequent artifacts from occlusal restorations or prosthesis limited the usefulness of simulated surgery involving occlusion. We prepared three-dimensional(3D) solid model from CT data and integrated the 3D solid model with dental cast using a face-bow transfer technique combined with skeletal reference measurement and confirmation with cephalometric radiographs. With this simple and easy method, it was possible to predict bony interference between the proximal and distal segment of the mandible so that we can prevent condylar displacement after sagittal split ramus osteotomy of the mandible with prominent asymmetry. The method error was within 2mm and it seemed to be useful in preoperative planning for maxillofacial surgery with maxillo-mandibular occlusal change.

• 한국콘텐츠학회논문지
• /
• 제11권12호
• /
• pp.619-628
• /
• 2011

일반적으로 비전기반 3차원 인체 포즈 인식 기술은 HCI(Human-Computer Interaction)에서 인간의 제스처를 전달하기 위한 방법으로 사용된다. 특수한 환경에서 단순한 2차원 움직임 포즈만 인식할 수 있는 2차원 포즈모델 기반 인식 방법에 비해 3차원 관절을 묘사한 포즈모델은 관절각에 대한 정보와 신체 부위의 모양정보를 선행지식으로 사용할 수 있어서 좀 더 일반적인 환경에서 복잡한 3차원 포즈도 인식할 수 있다는 장점이 있다. 이 논문은 인체의 3차원 관절 정보를 이용한 포즈 인식 기술을 인터페이스로 활용한 상호작용 게임 콘텐츠 개발에 관해 기술한다. 제안된 시스템에서 사용되는 포즈는 인체 관절 중 14개 관절의 3차원 위치정보를 이용해서 구성한 포즈 템플릿과 현재 사용자의 포즈를 비교해 인식된다. 이 방법을 이용하여 제작된 시스템은 사용자가 부가적인 장치의 사용 없이 사용자의 몸동작만으로 자연스럽게 게임 콘텐츠를 조작할 수 있도록 해준다. 제안된 3차원 인식 기술을 게임 콘텐츠에 적용하여 성능을 평가한다. 향후 다양한 환경에서 더욱 강건하게 포즈를 인식할 수 있는 연구를 수행할 계획이다.