• 한국CDE학회논문집
• /
• 제19권1호
• /
• pp.68-79
• /
• 2014

Human model simulation has been widely used in various industrial areas such as ergonomic design, product evaluation and characteristic analysis of work-related musculoskeletal disorders. However, the process of building digital human models and capturing their behaviors requires many costly and time-consuming fabrication iterations. To overcome the limitations of this expensive and time-consuming process, many studies have recently presented a markerless motion capture approach that reconstructs the time-varying skeletal motions from optical devices. However, the drawback of the markerless motion capture approach is that the phenomenon of occlusion of motion data occurs in real-time human simulation. In this study, we propose a systematic method of discriminating missing or inaccurate motion data due to motion occlusion and interpolating a sequence of motion frames captured by a markerless depth camera.

• 정보처리학회논문지:소프트웨어 및 데이터공학
• /
• 제10권11호
• /
• pp.491-500
• /
• 2021

본 연구에서는 MS Kinect v2 RGBD 카메라 기반의 Human-Skeleton Keypoints와 2-Stacked Bi-LSTM 모델을 이용하여 낙상 행위를 탐지하는 방법을 제안한다. 기존의 연구는 RGB 영상에서 OpenPose 등의 딥러닝 모델을 이용하여 골격 정보를 추출한 후 LSTM, GRU 등의 순환신경망 모델을 이용해 인식을 수행하였다. 제안한 방법은 카메라로부터 골격정보를 바로 전달 받아 가속도 및 거리의 2개의 시계열 특징을 추출한 후 2-Stacked Bi-LSTM 모델을 이용하여 낙상 행위를 인식하였다. 어깨, 척추, 골반 등 주요 골격을 대상으로 중심관절을 구하고 이 중심관절의 움직임 가속도와 바닥과의 거리를 특징으로 제안하였다. 추출된 특징은 Stacked LSTM, Bi-LSTM 등의 모델과 성능비교를 수행하였고 GRU, LSTM 등의 기존연구에 비해 향상된 검출 성능을 실험을 통해 증명하였다.

• 한국정밀공학회지
• /
• 제25권5호
• /
• pp.155-163
• /
• 2008

This study investigated biomechanical response through the 3-dimensional virtual skeletal model developed and validated. Ten male subjects in standing posture were exposed to whole body vibrations and measured acceleration on anatomical of interest (head, $7^{th}$ cervical, $10^{th}$ thoracic, $4^{th}$ lumbar, knee joint and bottom of the vibrator). Three dimensional virtual skeletal model and vibration machine were created by using BRG LifeMOD and MSC.ADAMS. The results of forward dynamic analysis were compared with results of experiment. The results showed that the accuracy of developed model was $73.2{\pm}19.2%$ for all conditions.

• BMB Reports
• /
• 제46권6호
• /
• pp.328-333
• /
• 2013

Many bioactive molecules like recombinant human bone morphogenetic protein 2 (rhBMP-2) have been developed for mineralized bone grafts, for which proper scaffolds are necessary to successfully apply the bioactive molecules. In this study, we tested the osteogenic efficacy of rhBMP-2 produced in-house in combination with gelatin sponge as the scaffold carrier in a rabbit radial defect model. The efficacy of the rhBMP-2 was determined by alkaline phosphatase activity assay of C2C12 cells. Two groups of ten rabbits each were treated with rhBMP-2/gelatin sponge, or gelatin sponge only. At 4 weeks, rhBMP-2/gelatin sponge grafts showed more bone regeneration than gelatin sponge grafts, as determined by X-ray radiography, micro-computed tomography, and histological analyses. At 8 weeks, rhBMP-2/gelatin sponge grafts exerted much stronger osteogenic effects. The study demonstrates the improved osteogenic efficacy of the rhBMP-2/gelatin sponge grafts in a rabbit radial bone defect model acting as a bone-inductive material.

• ETRI Journal
• /
• 제39권2호
• /
• pp.181-190
• /
• 2017

The movements of the human body are difficult to capture owing to the complexity of the three-dimensional skeleton model and occlusion problems. In this paper, we propose a motion capture system that tracks dynamic human motions in real time. Without using external markers, the proposed system adopts multiple depth sensors (Microsoft Kinect) to overcome the occlusion and body rotation problems. To combine the joint data retrieved from the multiple sensors, our calibration process samples a point cloud from depth images and unifies the coordinate systems in point clouds into a single coordinate system via the iterative closest point method. Using noisy skeletal data from sensors, a posture reconstruction method is introduced to estimate the optimal joint positions for consistent motion generation. Based on the high tracking accuracy of the proposed system, we demonstrate that our system is applicable to various motion-based training programs in dance and Taekwondo.

• 한국전자통신학회논문지
• /
• 제8권9호
• /
• pp.1407-1412
• /
• 2013

인간의 건강한 생활을 위해서는 자세 및 골격구조가 중요하며, 이것은 평소의 생활습관과 걸음걸이에 의해서 영향을 받아 변형될 수 있다. 인간의 걸음걸이형태로는 크게 바른걸음, 팔자걸음, 안짱걸음으로 구분할 수 있으며, 이러한 걸음걸이형태를 분석하여 바른자세를 유지하는데 도움이 될 수 있다. 본 논문에서는 스트레인 센서를 이용하여 걸음걸이 패턴을 분석하는 신발을 개발하였으며, 제작된 신발로 걸음걸이 패턴을 구분하여 분석할 수 있었다.

• 한국정밀공학회지
• /
• 제21권5호
• /
• pp.188-202
• /
• 2004

This research was designed to investigate biomechanical aspects of the evolution based on the hypothesis of dynamic cooperative interactions between the locomotion pattern and the body shape in the evolution of human bipedal walking The musculoskeletal model used in the computer simulation consisted of 12 rigid segments and 26 muscles. The nervous system was represented by 18 rhythmic pattern generators. The genetic algorithm was employed based on the natural selection theory to represent the evolutionary mechanism. Evolutionary strategy was assumed to minimize the cost function that is weighted sum of the energy consumption, the muscular fatigue and the load on the skeletal system. The simulation results showed that repeated manipulations of the genetic algorithm resulted in the change of body shape and locomotion pattern from those of chimpanzee to those of human. It was suggested that improving locomotive efficiency and the load on the musculoskeletal system are feasible factors driving the evolution of the human body shape and the bipedal locomotion pattern. The hypothetical evolution method employed in this study can be a new powerful tool for investigation of the evolution process.

• Nutritional Sciences
• /
• 제7권2호
• /
• pp.70-75
• /
• 2004

The objective of this study was to examine diet-induced changes in the expression of UCP2 mRNA in the liver and UCP3 mRNA in the skeletal muscle of mice fed a high-sucrose or high-fat diet. Male ICR mice, aged 4 weeks, were divided into three dietary groups and fed control (N) or modified AIN-76 high-sucrose (US) or high-fat (HF) diets for 12 weeks. The serum total cholesterol (TC) and LDL-cholesterol concentrations of the HF group were significantly higher than those of the N and HS groups. The hepatic TC and triglyceride contents of the HS and HF groups were also significantly higher than those of the N group. The HS diet group had higher serum leptin and insulin levels compared to those of the HF group. Hepatic UCP2 mRNA expression was significantly higher in the HS group than in the N group, but the level in the HF group did not differ from that of the N group. Muscular UCP3 mRNA level was significantly higher in the HF group and especially in the HS group than in N the group. We observed that two gene (UCP2, 3) levels exhibited a similar tendency. These results suggest that UCPs mRNA levels and energy expenditure may be altered or controlled by various dietary patterns. Further research is needed to elucidate the effects of diet on the regulation of many obesity-related genes.

• 보존과학연구
• /
• 통권32호
• /
• pp.171-183
• /
• 2011

본 연구는 충청남도 부여군 규암면 오수리 유적에서 발굴된 인골 4개체를 대상으로 조직학, 분자유전학, 골화학 분석 등 종합적인 연구를 통해 이들의 상관관계를 규명하고자 하였다. 실체현미경을 통해 인골 시료의 골조직 단면 구조를 관찰함으로써 각 시료의 조직학적 보존 상태를 단계별로 구분하였고, 잔존하는 단백질의 보존 상태는 콜라겐을 추출하여 수율을 측정함으로써 평가하였다. 또한 미토콘드리아 cytochrome b 유전자를 이용한 실시간 유전자 증폭법을 이용하여 각각의 인골 시료에 잔존하는 미토콘드리아 DNA의 상대적 보존량 및 복제수를 분석하였으며, 미토콘드리아 과변위부위의 염기서열을 동정하였다. 본 연구 결과 인골 시료의 조직학적 보존정도, 콜라겐 단백질의 잔존량, 미토콘드리아 DNA의 복제수는 상호 긍정적인 연관관계로 나타났다. 이 연구는 출토 인골의 생물 화학적 분석 가능성을 예측하기 위한 특성지표 연구의 중요자료로 활용 될 수 있을 것이다.

• 한국정보통신학회논문지
• /
• 제6권7호
• /
• pp.1084-1088
• /
• 2002

현재 수많은 의료기관 및 의학기관에서는 실습 및 교육에 대해 만족할 만한 환경이 구축되어 있지 않아 적절한 실습과 교육이 이뤄지지 못하고 있는 실정이다. 본 논문에서는 가상 인체와 소화작용 동영상을 인터넷상에서 3차원으로 구현하여 전공의뿐 만 아니라 일반인들도 원하는 대상을 직접 관찰해 봄으로써 정보획득을 쉽게 할 수 있게끔 하였다. 따라서 본 논문에서는 가상 인체 탐색 프로그램을 제작하여 Web 3D 기술을 대표하는VRML을 이용해 3차원 영상을 구현함으로써 인체와 소화작용에 대한 입체 생김새를 깨닫는데 도움이 될 수 있도록 실감나게 인터넷상에서 제공하여 교육 및 의료실습에 효과적으로 이용할 수 있게 하였다.