• 제목/요약/키워드: Multiple Joints

검색결과 162건 처리시간 0.039초

Damage detection in truss bridges using transmissibility and machine learning algorithm: Application to Nam O bridge

  • Nguyen, Duong Huong;Tran-Ngoc, H.;Bui-Tien, T.;De Roeck, Guido;Wahab, Magd Abdel
    • Smart Structures and Systems
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    • 제26권1호
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    • pp.35-47
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    • 2020
  • This paper proposes the use of transmissibility functions combined with a machine learning algorithm, Artificial Neural Networks (ANNs), to assess damage in a truss bridge. A new approach method, which makes use of the input parameters calculated from the transmissibility function, is proposed. The network not only can predict the existence of damage, but also can classify the damage types and identity the location of the damage. Sensors are installed in the truss joints in order to measure the bridge vibration responses under train and ambient excitations. A finite element (FE) model is constructed for the bridge and updated using FE software and experimental data. Both single damage and multiple damage cases are simulated in the bridge model with different scenarios. In each scenario, the vibration responses at the considered nodes are recorded and then used to calculate the transmissibility functions. The transmissibility damage indicators are calculated and stored as ANNs inputs. The outputs of the ANNs are the damage type, location and severity. Two machine learning algorithms are used; one for classifying the type and location of damage, whereas the other for finding the severity of damage. The measurements of the Nam O bridge, a truss railway bridge in Vietnam, is used to illustrate the method. The proposed method not only can distinguish the damage type, but also it can accurately identify damage level.

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.

일개 농촌 지역사회 노인들의 건강증진사업 우선순위 비교 (Heath Promotion Priorities of Older Adults in a Rural Community)

  • 이보영;조희숙;이혜진;유승현
    • 지역사회간호학회지
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    • 제19권1호
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    • pp.57-65
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    • 2008
  • Purpose: The purpose of this study is to assess the priorities of health promotion for older adults in the rural community. The study attempts to display demographic characteristics subjective health status and chronic diseases status of the older adults. Methods: We surveyed 384 senior residents in a community via face-to-face interviews in their homes, who were selected by proportional random sampling. We analysed the frequency, multiple responses and $X^2$ by SPSS 12.0K. Results: The mean of subjective health status was $54.04{\pm}21.69$ with a maximum of 100. Our study found that the high priorities in health promotion for older adults were prevention and management of hypertension and diabetes, strengthening of joint and muscles, cancer screening and physical exercise. Prevention of depression and social activities were low priorities. Strengthening of joints and muscles was a high priority among women while smoking cessation and social activities were high priorities of men. Conclusion: In conclusion, health promotion priorities of older adults differed by gender and subjective health status. Disease-related priorities received more attention than psycho-social health priorities. This study suggests comparing the priorities regionally and nationally.

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Ti 합금을 이용한 항공기용 Flexible PTO 샤프트 개발 시험 (Development Test for Flexible PTO Shaft Made of Ti Alloy for Aircraft)

  • 이주홍;강보식;유현석;이지만;조해용
    • 대한기계학회논문집A
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    • 제40권8호
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    • pp.759-765
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    • 2016
  • 항공기 등에 사용되는 Flexible PTO(Power Take-Off) 샤프트는 스프링 특성을 좋게 하기 위해 여러장의 얇은 멤브레인을 용접한 형태로 1950년대에 이미 개발됐으며, AMAD(Aircraft Mounted Accessory Drive) 기어박스와 EMAD(Engine Mounted Accessary Drive) 기어박스 사이에서 회전동력을 전달한다. 이런 종류의 샤프트는 가볍고 특히 스프링 특성이 좋기 때문에 축 정렬이 틀어진 고속회전 상태에서도 안정적으로 회전동력을 전달할 수 있어 대부분의 전투기에 사용된다. 이번 연구에서 티타늄 합금으로 개발된 Flexible PTO 샤프트의 구조해석을 통해 제품의 안전성을 확인하였고, 실제 실험실에서 진행된 고속회전 시험에서 굽힘과 비틀림 부하를 동시에 인가하여 샤프트의 고주기 피로에 대한 내성을 실증하였다. 또한, 고주기 피로 시험 조건에서 항공기용 볼 조인트의 마모 특성 분석을 통해 수명을 예측하였다.

Mucopolysaccharidoses in Taiwan

  • Lin, Hsiang-Yu;Chuang, Chih-Kuang;Lin, Shuan-Pei
    • Journal of mucopolysaccharidosis and rare diseases
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    • 제4권1호
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    • pp.14-20
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    • 2018
  • Mucopolysaccharidoses (MPSs) are a group of rare inherited metabolic disorders caused by specific lysosomal enzyme deficiencies leading to the sequential degradation of glycosaminoglycans, causing substrate accumulation in various cells and tissues and progressive multiple organ dysfunction. The rare disease medical care team at Mackay Memorial Hospital in Taiwan has been dedicated to the study of MPSs for more than 20 years. Since 1999, more than 50 academic papers focusing on MPSs have been published in international medical journals. Topics of research include the following items regarding MPSs: incidence, natural history, clinical manifestations, gene mutation characteristics, cardiac function, bone mineral density, sleep studies, pulmonary function tests, hearing assessments, percutaneous endoscopic gastrostomy, anesthetic experience, imaging analysis, special biochemical tests, laboratory diagnostics, global expert consensus conferences, prenatal diagnosis, new drug clinical trials, newborn screening, and treatment outcomes. Of these published academic research papers, more than half were cross-domain, cross-industry, and international studies with results in cooperation with experts from European, American and other Asian countries. A cross-specialty collaboration platform was established based on high-risk population screening criteria with the acronym "BECARE" (Bone and joints, Eyes, Cardiac and central nervous system, Abdomen and appearance, Respiratory system, and Ear, nose, and throat involvement). Through this platform, orthopedic surgeons, rheumatologists, ophthalmologists, cardiologists, rehabilitation physicians, gastroenterologists, otorhinolaryngologists, and medical geneticists have been educated with regards to awareness of suspected cases of MPSs patients to allow for a further confirmative diagnosis of MPSs. Because of the progressive nature of the disease, an early diagnosis and early multidisciplinary therapeutic interventions including surgery, rehabilitation programs, symptom-based treatments, hematopoietic stem cell transplantation, and enzyme replacement therapy, are very important.

고혈압과 뇌혈관염이 동반된 상태에서 뇌증을 보인 Henoch-Schonlein Purpura Nephritis 1례 (A Case of Henoch-Schonlein Purpura Nephritis Complicating Encephalopathy Accompanied by Hypertension and Cerebral Vasculitis)

  • 최희라;김어진;최명범;임재영;박찬후;우향옥;윤희상
    • Clinical and Experimental Pediatrics
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    • 제46권10호
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    • pp.1040-1043
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    • 2003
  • 저자들은 9세 남아에서 고혈압과 뇌혈관염이 동반된 상태에서 뇌증을 보인 HSP 신염 1례를 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

족근-중족 관절 골절 탈구의 치료경험 (Treatment for Tarsometatarsal Fracture-Dislocation)

  • 정영기;유정한;박용욱;노동근;하성한
    • 대한족부족관절학회지
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    • 제1권2호
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    • pp.112-118
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    • 1997
  • Tarsometatarsal fracture-dislocation is uncommon but severe lesion. Since this lesion is sometimes difficult to recognize by roentgenography, it is easily overlooked. Three patients were treated with open reduction and internal fixation with 3.5 mm cannulated screw and K-wire, two had treatment with open reduction and internal fixation with 3.5 mm cannulated screw only and two had treatment with dosed reduction and short leg cast only between January 1994 and May 1996. The duration of follow-up ranged from twelve to twenty-nine months after the diagnosis. Results were assessed by a subjective questiormaire, physical examination, and radiographic analysis. Multiple fixation techniques for maintaining the reduction of tarsometatarsl joint have been introduced. We recent]y used the 3.5 mm cannulated screw for internal fixation of the tarso-first and second metatarsal fracture-dislocation. We think cannulated screw fixation has several advantages; 1. The cannulated screw fixation is more rigid than the K-wire fixation. 2. There is an decreased risk of screw breakage with early weight bearing. 3. It is possible to compress the involved joints, if necessary. There were no disability in all patients. One patient who was treated with delayed open reduction and internal fixation with 3.5 mm cannulated screw and K-wire had a radiographic mild degenerative arthritis. And one patient who was treated with dosed reduction and short leg cast had a mild metatarsus adductus. But. these two patients were symptom free. There was no correlation between the severity of the diastasis and the patient s functional result.

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임무에 따른 하박 교체형 고 가반하중 양팔로봇의 설계: 구난 및 물체 핸들링 (Design of High Payload Dual Arm Robot with Replaceable Forearm Module for Multiple Tasks: Human Rescue and Object Handling)

  • 김휘수;박동일;최태용;도현민;김두형;경진호;박찬훈
    • 로봇학회논문지
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    • 제12권4호
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    • pp.441-447
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    • 2017
  • Robot arms are being increasingly used in various fields with special attention given to unmanned systems. In this research, we developed a high payload dual-arm robot, in which the forearm module is replaceable to meet the assigned task, such as object handling or lifting humans in a rescue operation. With each forearm module specialized for an assigned task (e.g. safety for rescue and redundant joints for object handling task), the robot can conduct various tasks more effectively than could be done previously. In this paper, the design of the high payload dual-arm robot with replaceable forearm function is described in detail. Two forearms are developed here. Each of forearm has quite a different goal. One of the forearms is specialized for human rescue in human familiar flat aspect and compliance parts. Other is for general heavy objects, more than 30 kg, handling with high degree of freedom more than 7.

결절홍반을 동반한 폐결핵환자에 나타난 Poncet병 1예 (A Case of Poncet's Disease in a Patient with Pulmonary Tuberculosis Accompanying Erythema Nodosum)

  • 한나;이수경;김태진;송윤석;정선호;양경호;최성진;신원혁
    • Tuberculosis and Respiratory Diseases
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    • 제71권3호
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    • pp.221-224
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    • 2011
  • Poncet's disease is an aseptic polyarthritis developing in the presence of active Tuberculosis occurring elsewhere, and is not due to direct involvement of joints but to an immunological reaction to tuberculoprotein. We experienced a case of Poncet's disease accompanying erythema nodosum in a 55-year-old female patient with pulmonary tuberculosis. She had multiple tender erythematous nodules on both lower limbs for 3 months and a cough and sputum from one month ago. She felt severe pain in both knees and ankles with swelling one week before admission. Her chest X-ray, computed tomography (CT) scan and positive sputum AFB stain results revealed that she had active pulmonary tuberculosis accompanying erythema nodosum and aseptic polyarthritis. Her arthritis and erythema nodosum were dramatically improved within four weeks after anti-tuberculosis therapy. We report a case of Poncet's disease in pulmonary tuberculosis accompanying erythema nodosum.

단일 카메라를 이용한 동역학 기반의 보행 동작 추적 (Tracking a Walking Motion Based on Dynamics Using a Monocular Camera)

  • 유태근;최재림;김덕원
    • 전자공학회논문지SC
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    • 제49권1호
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    • pp.20-28
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    • 2012
  • 보행을 관찰하고 객관적인 정보를 추출하여 그 기능을 평가하는 것을 보행 분석이라고 한다. 최근 사용되는 보행 측정 장비들은 다수의 카메라, 지면 반력 측정 장치로 구성되어 고가이며, 이를 설치할 넓은 장소를 필요로 한다는 단점이 있다. 본 연구에서는 이러한 문제점을 해결하기 위해 단일 카메라를 통해 얻은 영상에서 마커 없이 인체의 3차원 보행 동작을 측정하는 기법을 제안한다. 파티클 필터를 사용하여 훈련 데이터와 보행에 관한 사전 정보 없이 사람의 동작을 추적한다. 인체와 지면에 관한 동역학을 통해 물리적으로 합당한 인체의 동작들을 생성하였다. 보행 영상에서 계산한 모든 관절의 평균 에러는 제안한 방법에서 $12.4^{\circ}$로, 기존 파티클 필터의 에러 $34.6^{\circ}$보다 작았다. 이러한 결과를 바탕으로 단일 카메라만으로 보행을 정량적으로 측정하여 기존 복잡한 장비를 대체할 수 있는 가능성을 제시하였다.