• 제목/요약/키워드: Human head model

검색결과 186건 처리시간 0.021초

A Review of Rat Models of Avascular Necrosis of the Femoral Head Treated with Natural Extracts

  • Go-Woon, Kim;Hyoung-Yong, Park;Yeon-Cheol, Park
    • Journal of Acupuncture Research
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    • 제39권4호
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    • pp.239-248
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    • 2022
  • To determine the effect of Korean medicine treatment of avascular necrosis of the femoral head (ANFH) this study reviewed both single ingredients and bioactive compounds in the treatment of ANFH in a rat model. Literature was retrieved from PubMed and Google Scholar using the keywords "femur head necrosis," "natural extract," and "rat." The data from studies analyzed included: rats' characteristics, development methods of ANFH, natural extracts administration, observation methods, and outcome indicators. Two independent researchers screened all articles retrieved and 26 studies were chosen. The most used rat species was the Sprague Dawley rat (76.9%). To induce ANFH, steroid injections (46.2%), and oral gavage (53.8%) were typically used. Studies focused mainly on factors affecting bone formation (65.3%), and apoptosis (53.8%). Research on ANFH focused on using traditional natural substances mentioned in classical literature to confirm its effectiveness against anti-inflammation, osteogenesis, and cell death. ANFH has a diverse etiology, therefore research models such as genetic analysis of human-derived samples from ANFH patients may shed more light on the condition. Moreover, research into herbal medicines and pharmacoacupuncture treatment of ANFH should precede.

낙하 충격을 받는 다점 구속 장치를 착용한 헬기 승무원의 상해도 평가에 관한 연구 (A Study on the Injury Assessment of Helicopter's Crew with Multi Point Restraint System under Drop Impact)

  • 이중현;이영신
    • 대한기계학회논문집A
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    • 제33권6호
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    • pp.590-599
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    • 2009
  • In this paper, a method of modeling seat belts on crew seat during dynamic seat testing was studied. The body segments of the occupant were modeled with joints. The joints consisted with various stiffnesses, dampings, and frictions. Three types of seat belt restraint systems were investigated. The analysis for on the injury assessment of helicopter's crew under drop impact was conducted. The effectiveness of the seat belt system for crashworthiness and safety was evaluated. As the results of impact analysis, head, neck and spine of the crew can be easily damaged in the vertical direction more than the longitudinal direction. Based on the verified model, behavior of human body was studied with three-point restraint systems. The displacement and injury level of the 12-point restraint system was the smallest.

Development of Korean Male Body Model for Computational Dosimetry

  • Lee, Ae-Kyoung;Choi, Woo-Young;Chung, Min-Suk;Choi, Hyung-Do;Choi, Jae-Ick
    • ETRI Journal
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    • 제28권1호
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    • pp.107-110
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    • 2006
  • The dimensions of the human body vary by age, sex, and race. The internal structure and outer dimensions of a body exposed to an electromagnetic field is important for accurate dosimetry. The average physical size of Korean adult males between the ages 18 to 24 was investigated, and a male volunteer was selected whose physical condition is within the physical standards, ${\pm}5%$. Magnetic resonance images and partially computerized tomography images of the volunteer were acquired. The intervals between the transverse images were 1 mm for the head and 3 mm for the rest of the body. About 30 different tissues were manually classified by an anatomist on the raw images, and the segmented images were implemented in the form of a text file appropriate for numerical formulation.

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통계학적 학습을 이용한 머리와 어깨선의 위치 찾기 (Localizing Head and Shoulder Line Using Statistical Learning)

  • 권무식
    • 한국통신학회논문지
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    • 제32권2C호
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    • pp.141-149
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    • 2007
  • 영상에서 사람의 머리위치를 찾는 문제에 있어서 어깨선 정보를 이용하는 것은 아주 유용하다. 영상에서 머리 외곽선과 어깨선의 형태는 일정한 변형을 유지하면서 같이 움직이므로 이를 ASM(Active Shape Model) 기법을 사용해서 통계적으로 모델링 할 수 있다. 그러나 ASM 모델은 국부적인 에지나 그래디언트에 의존하므로 배경 에지나 클러터 성분에 민감하다. 한편 AAM(Active Appearance Model) 모델은 텍스쳐 등을 이용하지만, 사람의 피부색, 머리색깔, 옷 색깔 등의 차이로 인해서 통계적인 학습방법을 쓰기가 어렵고, 전체 비디오에서 외모(Appearance)가 시간적으로 변한다. 따라서, 본 논문에서는 외모(Apperance) 모델을 변화에 따라 바꾸는 대신, 영상의 각 화소를 머리, 어깨, 배경으로 구분하는 분별적 외모 모델(discriminative appearance)를 사용한다. 실험을 통해서 제안된 방법이 기존의 기법에 비해서 포즈변화와 가려짐, 조명의 변화 등에 강인함을 보여준다. 또한 제안된 기법은 실시간으로 작동하는 장점 또한 가진다.

차량 시뮬레이터 접목을 위한 실시간 인체거동 해석기법 (Real-Time Analysis of Occupant Motion for Vehicle Simulator)

  • 오광석;손권;최경현
    • 대한기계학회논문집A
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    • 제26권5호
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    • pp.969-975
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    • 2002
  • Visual effects are important cues for providing occupants with virtual reality in a vehicle simulator which imitates real driving. The viewpoint of an occupant is sensitively dependent upon the occupant's posture, therefore, the total human body motion must be considered in a graphic simulator. A real-time simulation is required for the dynamic analysis of complex human body motion. This study attempts to apply a neural network to the motion analysis in various driving situations. A full car of medium-sized vehicles was selected and modeled, and then analyzed using ADAMS in such driving conditions as bump-pass and lane-change for acquiring the accelerations of chassis of the vehicle model. A hybrid III 50%ile adult male dummy model was selected and modeled in an ellipsoid model. Multibody system analysis software, MADYMO, was used in the motion analysis of an occupant model in the seated position under the acceleration field of the vehicle model. Acceleration data of the head were collected as inputs to the viewpoint movement. Based on these data, a back-propagation neural network was composed to perform the real-time analysis of occupant motions under specified driving conditions and validated output of the composed neural network with MADYMO result in arbitrary driving scenario.

무속 공간모형에 의한 남사마을 공간 해석에 관한 연구 (An Interpretative Study on the Nam-Sa Village Space by Shamanistic Space Model)

  • 김동찬;이윤수;임상재
    • 한국조경학회지
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    • 제27권2호
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    • pp.95-107
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    • 1999
  • Shamanism is an ancient culture that is also considered as a religious rite by most of people. So, shamanism is an important part of Korean tradition and should be a significant base to the Korean exterior space organization theme. However in the field of Landscape architecture th principle of exterior spacing has not yet clearly been identified as shamanistic. Therefore believe that this study can exhibit a model for the study of shaministic space language and its application to one of Korean's village Namsa. The results of this study are summarized below; 1. Extracted models are Unspecialized· Circular·Coninuous space. These are analyzed on the basis of the shaministic space language. Also shaministic space languages are based with Korean common belief of eternal human identify, circular view of the world. 2. Applying the shamanistic space models to Namsa village shows that shamanistic space models follow the Korean space organization principle. Some area of the village do not apply, because they were built on the structure of the social hierarchy between families or the difference between head households and collateral households. 3. Applying the shamanistic space model to Namsa village shows that the shamanistic space model follows the Korean space organization principle. Therefore can say that Namsa village was built by a shamanistic system that pursued eternal human identity.

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머리 진동 측정치의 불확도 인자들에 관한 연구 (Study on Uncertainty Factors of Head Vibration Measurements)

  • 정완섭;김영태;류제담;홍동표
    • 한국소음진동공학회논문집
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    • 제15권1호
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    • pp.20-28
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    • 2005
  • 이 논문에서는 기존의 6-축 혹은 9-축 머리진동 측정장치(bite-bar)를 이용한 머리진동 측정에서 직면하는 불확도 인자들에 대한 문제점을 우선 소개한다. 이들 불확도 인자들은 머리의 6-자유도 운동 성분의 추정에 필요한 모든 측정 요소들을 측정하지 않았다는 한계점에서 유발함을 보인다. 이러한 문제점을 극복하기 위하여 4개의 3축 가속도 센서로 구성된 새로운 머리진동 측정장치(12-axis bite-bar)의 모델을 제안한다. 본 모델은 측정 기준점에서의 선형 3축 가속도 뿐 아니라 3축 각 가속도와 함께 6 종의 2차 각속도 성분들의 추정 또한 가능하게 한다. 이러한 12 성분의 추정 모델로부터 비로소 머리의 임의 점에서 6-자유도 운동 성분의 계산이 가능함을 이론적으로 규명한다. 이러한 이론적 배경에 기반을 두고 설계 제작된 12-축 머리진동 장치(12-axis bite-bar)를 소개한다. 본 장치를 이용하여 얻어진 실험 결과 소개 뿐 아니라 기존의 측정장치의 측정 결과와 비교 분석 내용을 소개한다.

상지 외골격 로봇 제어를 위한 인체 팔 동작의 기구학 및 동역학적 분석 - 파트 1: 시스템 모델 및 기구학적 제한 (Analysis on Kinematics and Dynamics of Human Arm Movement Toward Upper Limb Exoskeleton Robot Control Part 1: System Model and Kinematic Constraint)

  • 김현철;이춘영
    • 제어로봇시스템학회논문지
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    • 제18권12호
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    • pp.1106-1114
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    • 2012
  • To achieve synchronized motion between a wearable robot and a human user, the redundancy must be resolved in the same manner by both systems. According to the seven DOF (Degrees of Freedom) human arm model composed of the shoulder, elbow, and wrist joints, positioning and orientating the wrist in space is a task requiring only six DOFs. Due to this redundancy, a given task can be completed by multiple arm configurations, and thus there exists no unique mathematical solution to the inverse kinematics. This paper presents analysis on the kinematic and dynamic aspect of the human arm movement and their effect on the redundancy resolution of the human arm based on a seven DOF manipulator model. The redundancy of the arm is expressed mathematically by defining the swivel angle. The final form of swivel angle can be represented as a linear combination of two different swivel angles achieved by optimizing different cost functions based on kinematic and dynamic criteria. The kinematic criterion is to maximize the projection of the longest principal axis of the manipulability ellipsoid for the human arm on the vector connecting the wrist and the virtual target on the head region. The dynamic criterion is to minimize the mechanical work done in the joint space for each two consecutive points along the task space trajectory. As a first step, the redundancy based on the kinematic criterion will be thoroughly studied based on the motion capture data analysis. Experimental results indicate that by using the proposed redundancy resolution criterion in the kinematic level, error between the predicted and the actual swivel angle acquired from the motor control system is less than five degrees.

자기공명영상이 인체에 미치는 영향 : 치아임플란트 재료에 따른 차이 분석 (Effects of Magnetic Resonance Imaging on the Human Body : Analysis of differences according to Dental Implant Material)

  • 최대연;김동현
    • 한국방사선학회논문지
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    • 제12권4호
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    • pp.481-489
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    • 2018
  • Brain MRI 검사에서는 영상을 얻기 위해 RF Pulse를 인체에 조사하게 되는데 이때 조사된 RF Pulse 에너지의 상당부분은 우리 몸에 그대로 흡수되게 되고 이로 인해 인체의 온도가 상승하게 되는데 노출정도에 따라 인체에 영향을 주게 된다. 그리고 같은 RF Pulse 에너지를 주었더라도 인체에 금속이 삽입되었다면 금속으로 인한 전자파 전도도가 증가하기 때문에 SAR가 증가하고 체온도 변화하게 된다. 이에 Brain MRI검사 시 치아 임플란트의 재료에 따라 발생되는 두부 전체의 SAR와 온도의 변화를 비교 분석하고자 한다. 실험은 인체 두부모델에 1.5Tesla MRI장비에서 발생되는 64MHz RF Pulse 주파수, 3.0Tesla MRI장비에서 발생되는 128MHz RF Pulse 주파수를 조사한 뒤 치아 임플란트 재료를 Titanium과 $Al_2O_3$로 변화시킨 경우 두부 전체의 SAR와 온도 변화를 알아본다. 치아 임플란트 재료의 변화에서 Titanium을 사용하였을 때, 두부 전체의 SAR와 온도는 높게 나타났다. 하지만 $Al_2O_3$을 사용하였을 때, Titanium보다 두부 전체의 SAR와 온도는 낮게 나타났다. 치아 임플란트의 재료는 금속의 비중이 작은 경금속이면서 전기적 도체인 Titanium과 비교했을 때 전기전도도가 낮은 전기적 부도체인 $Al_2O_3$에서 두부 전체의 SAR와 온도는 낮게 나타났다. 치아 임플란트 재료가 Titanium 일 경우 SAR의 최대값은 제한치보다 월등히 높기 때문에 향후 Titanium의 치아 임플란트 재료를 삽입한 환자가 Brain MRI 검사를 할 경우 환자의 생물학적 영향과 관련된 연구가 필요할 것이다. 또한, 치아 임플란트 시술 시 Titanium보다는 $Al_2O_3$ 재질의 치아 임플란트를 사용하는 것이 Brain MRI 검사에서 인체 두부 전체의 SAR와 온도를 감소시키는 방안이라는 점을 발견할 수 있었다.

A 3D Audio-Visual Animated Agent for Expressive Conversational Question Answering

  • Martin, J.C.;Jacquemin, C.;Pointal, L.;Katz, B.
    • 한국정보컨버전스학회:학술대회논문집
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    • 한국정보컨버전스학회 2008년도 International conference on information convergence
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    • pp.53-56
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    • 2008
  • This paper reports on the ACQA(Animated agent for Conversational Question Answering) project conducted at LIMSI. The aim is to design an expressive animated conversational agent(ACA) for conducting research along two main lines: 1/ perceptual experiments(eg perception of expressivity and 3D movements in both audio and visual channels): 2/ design of human-computer interfaces requiring head models at different resolutions and the integration of the talking head in virtual scenes. The target application of this expressive ACA is a real-time question and answer speech based system developed at LIMSI(RITEL). The architecture of the system is based on distributed modules exchanging messages through a network protocol. The main components of the system are: RITEL a question and answer system searching raw text, which is able to produce a text(the answer) and attitudinal information; this attitudinal information is then processed for delivering expressive tags; the text is converted into phoneme, viseme, and prosodic descriptions. Audio speech is generated by the LIMSI selection-concatenation text-to-speech engine. Visual speech is using MPEG4 keypoint-based animation, and is rendered in real-time by Virtual Choreographer (VirChor), a GPU-based 3D engine. Finally, visual and audio speech is played in a 3D audio and visual scene. The project also puts a lot of effort for realistic visual and audio 3D rendering. A new model of phoneme-dependant human radiation patterns is included in the speech synthesis system, so that the ACA can move in the virtual scene with realistic 3D visual and audio rendering.

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