• 제목/요약/키워드: strength design method

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Designing an Intelligent Rehabilitation Wheelchair Vehicle System Using Neural Network-based Torque Control Algorithm

  • Kim, Taeyeun;Bae, Sanghyun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권12호
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    • pp.5878-5904
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    • 2017
  • This paper proposes a novel intelligent wheelchair vehicle system that enables upper limb exercises, lower limb standing exercises and rehabilitation training in a daily life. The proposed system, which can be used to prevent at least the degeneration of body movements and further atrophy of musculoskeletal system functions, considers the characteristics and mobility of the old and the disabled. Its main purpose is to help the old and the disabled perform their daily activities as much as they can, minimizing the extent of secondary disabilities. In other words, the system will provide the old and the disabled with regular and quantitative rehabilitation exercises and diagnosis using the wheelchair-based upper/lower limb rehabilitation vehicle system and then verify their effectiveness. The system comprises an electric wheelchair, a biometric module to identify individual characteristics, and an upper/lower limb rehabilitation vehicle. In this paper the design and configuration of the developed vehicle is described, and its operation method is presented. Moreover, to verify the tracking performance of the proposed system, dangerous situations according to biosignal changes occurring during the rehabilitation exercise of a non-disabled examinee are analyzed and the performance of the upper/lower limb rehabilitation exercise function depending on muscle strength is evaluated through a neural network algorithm.

Vulnerability and seismic improvement of architectural heritage: the case of Palazzo Murena

  • Liberotti, Riccardo;Cluni, Federico;Gusella, Vittorio
    • Earthquakes and Structures
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    • 제18권3호
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    • pp.321-335
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    • 2020
  • The aim of the present contribution is to consider and underline the essential interactions among the historical knowledge, the seismic vulnerability assessment, the investigation experimental tools, the preservation of the architectural quality and the strengthening design in regard to architectural heritage conservation. These topics are argued in relation to Palazzo Murena in Perugia, designed in the eighteenth century by the famous Architect Luigi Vanvitelli, and currently headquarters of the city's University. Based on the surveys and the visual inspections, a preliminary a priori global analysis has been performed by means of the FME method. The obtained results permitted to plan an experimental tests campaign inclusive of structural health monitoring. The new achieved "knowledge" of the building allowed to refine the seismic safety assessment. In particular it was highlighted that the "mezzanine floor" can be a vulnerable element of the building with the collapse of its masonry walls. Preserving the architectural characteristics, a local reinforcement intervention is proposed for the above-mentioned level; this consists of the application of plaster with FRCM, assuring an adequate strength, without burden the masonry structure with additional weight, and therefore a decreasing of the seismic vulnerability. The necessity to consider, in this ongoing research, other local mechanisms is highlighted in the unfolding of the last part of work.

발반사마사지가 골관절염 환자의 신체적, 심리적, 생리적 지수에 미치는 영향 (Effects of Foot Reflexo-massage on Physical, Psychological, Physiological Parameters in Patients with Osteoarthritis)

  • 엄동춘
    • 성인간호학회지
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    • 제16권2호
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    • pp.276-287
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    • 2004
  • Purpose: This study was undertaken to investigate the effects of foot reflexo-massage on physical, psychological, and physiological parameters in patients with osteoarthritis of the knee. Method: This study was employed non-equivalent control group pretest-posttest time series experimental design. The subjects of this study were 47 elderly patients with osteoarthritis of the knee from two different nursing homes in Deajeon. The patients were divided into two groups; 26 patients in experimental group, the rest in control group. Each patient in experimental group received the 30-minute foot reflexo-massage, 3 times per week for 4 weeks. The dependent variables of each patient were measured before treatment, after 2 weeks and after 4 weeks during the treatment session. The collected data was analyzed using the Social Package Social Science(version 10.0) software program. Result: There were significant differences in the flexion angle of both knees; the flexion and extension muscle strength of both knees; systolic blood pressure; POMS; plantaris skin temperature and blood velocity of dorsalis pedis artery between the two groups over different the three measurement times. Conclusion: The results suggest that foot reflexo-massage could be an effective intervention to improve physical, psychological and physiological parameters for patients with knee osteoarthritis.

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항공기용 연료호스 제작시 최적 크림핑 직경에 관한 연구 (A Study on the Optimal Crimping Diameter of Aircraft Fuel Hoses in Manufacturing Process)

  • 전준영;김병탁
    • 동력기계공학회지
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    • 제18권1호
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    • pp.84-90
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    • 2014
  • The high pressure hoses are widely used for the vehicles, aircraft, and overall industries. The hose assembly is generally composed of a nipple, a socket and a hose with reinforcement layers to increase the tensile strength. To produce the hose assembly, crimping or swaging process is usually used to clamp its components to ensure the prevention of fluid leakage. Crimping is a cold-working technique to form a strong bond between the workpiece and a non-metallic component. The crimping stroke is a primary parameter to be determined in the metalworking process, and it plays an important role in hose performance. This study aims at investigating the optimal crimping stroke according to the size of aircraft high pressure hose by using MSC/MARC. It is supposed that the results can be useful to get the information about the crimping stroke in manufacturing process, even with the different size of a hose.

P/M법과 유도가열 공정변수가 6061 알루미늄 합금의 미세기공과 기계적 성질에 미치는 영향 (Effect of Process Parameters of P/M and Induction Heating on the Cell Morphology and Mechanical Properties of 6061 Aluminum Alloy)

  • 강충길;윤성원
    • 한국정밀공학회지
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    • 제20권6호
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    • pp.222-229
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    • 2003
  • The purpose of this study is to evaluate the mechanical properties of 6061 Al foams, which were fabricated by P/M and multi-step induction heating method, and to build the database, which is needed for computer aided modeling or foam components design. Aluminium foams, consisting of solid aluminium and large quantities of porosities, is widely used in automotive, aerospace, naval as well as functional applications because of its high stiffness at very low density, high impact energy absorption, heat and fire resistance, and greater thermal stability than any organic material. In this study, 6061 Al foams were fabricated for variation of fraction of porosities (%) according to porosities (%)-final heating temperature ( $T_{a3}$) curves. Mechanical properties such as compressive strength, energy absorption capacity, and efficiency were investigated to evaluate the feasibility of foams as crash energy absorbing components. Moreover, effect of the surface skin thickness on plateau stress and strain sensitivity of the 6061 Al foams with low porosities (%) were studied.d.

통신정보용 광대역 저잡음 증폭단 설계 및 구현 (Design and Fabrication of wideband low-noise amplification stage for COMINT)

  • 고민호
    • 한국전자통신학회논문지
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    • 제7권2호
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    • pp.221-226
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    • 2012
  • 본 논문에서는 광대역 (400 MHz~2000 MHz) 2단 증폭단을 설계, 제작 및 측정하였다. 제안한 증폭단은 새로운 구조의 이득제어 방식을 적용하여 고이득, 저잡음지수 및 높은 선형성 특성을 구현하였다. 증폭단은 공통 에미터 구조의 초단 증폭기 및 캐스코드 구조의 가변이득 증폭기. 입력신호의 크기를 감지하는 전력감지회로로 구성하였다. 제안한 증폭단은 설계 대역에서 전체이득 29 dB~37 dB, 잡음지수 1.5 dB을 나타내었고, 강전계 입력 조건에서 전력감지회로에서 발생되는 제어전압 2.0V인 조건에서 3차 상호변조 왜곡 신호의 크기는 측정 장비의 잡음레벨 보다 낮은 특성을 나타내어 높은 선형성 특성을 나타내었다.

Modeling time-dependent behavior of hard sandstone using the DEM method

  • Guo, Wen-Bin;Hu, Bo;Cheng, Jian-Long;Wang, Bei-Fang
    • Geomechanics and Engineering
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    • 제20권6호
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    • pp.517-525
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    • 2020
  • The long-term stability of rock engineering is significantly affected by the time-dependent deformation behavior of rock, which is an important mechanical property of rock for engineering design. Although the hard rocks show small creep deformation, it cannot be ignored under high-stress condition during deep excavation. The inner mechanism of creep is complicated, therefore, it is necessary to investigate the relationship between microscopic creep mechanism and the macro creep behavior of rock. Microscopic numerical modeling of sandstone creep was performed in the investigation. A numerical sandstone sample was generated and Parallel Bond contact and Burger's contact model were assigned to the contacts between particles in DEM simulation. Sensitivity analysis of the microscopic creep parameters was conducted to explore how microscopic parameters affect the macroscopic creep deformation. The results show that the microscopic creep parameters have linear correlations with the corresponding macroscopic creep parameters, whereas the friction coefficient shows power function with peak strength and Young's modulus, respectively. Moreover, the microscopic parameters were calibrated. The creep modeling curve is in good agreement with the verification test result. Finally, the creep curves under one-step loading and multi-step loading were compared. This investigation can act as a helpful reference for modeling rock creep behavior from a microscopic mechanism perspective.

노인의 건강증진을 위한 통합 운동프로그램 개발 (The Development of Integrative Exercise Program for the Elderly)

  • 한신희;박정모
    • 성인간호학회지
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    • 제14권3호
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    • pp.418-427
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    • 2002
  • Purpose: The Purpose of this research was to develop the integrative exercise program for the elderly. Method: The first step was to survey the elder's health status and general health problems. The second step was to design the exercise type, intensity, time and frequency. Result: 1. Elders who implement the integrative exercise program had weaker health status, lower physical performance and more depression than any other places. 2. The integrative exercise program developed the preparation stage composed of stretching and Yudongkong-Ki exercise, the central stage was composed of range of motion exercise, muscle strength exercise and aerobic exercise with favorite and popular Korean music. The finishing stage was composed of joint rounding and Yudongkong-Ki exercise. The exercise intensity was RPE(rating perceived exertion) 10-11, maximal pulse rate 40-60%, duration started from 20min to 50min and frequency is 2-3times/wk. Conclusion: The integrative exercise program developed by the researcher is tailored exercise that is more applicable to individual cases in community settings. Eventually, the program is safely applicable to the elders, and is expected to improve the elders' physical function and quality of life.

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축류에 놓인 환형 실린더 연료봉의 동적 안정성 기초해석 (Dynamic Stability Analysis of Annular Cylindrical Fuel Rod in Axial Flow)

  • 이강희;김형규;윤경호;이영호;김재용
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.264-267
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    • 2008
  • Dual-cooled fuel with inner and outer flow channel was proposed for high burup, next generation nuclear fuel design. The annular cylinder of dual cooled fuel has higher structural strength compared to the conventional one, but also have concerns about flow induced vibration due to an additional flow of inner channel and the difference of flow velocity in between inner and outer channel. In this study, the dynamic stability of flexible, annular cylinder was evaluated according to the flow variation and compared to the that of the conventional PWR fuel rod. Centrifugal and Coriolis force by the additional flow in the inner channel were added in the dynamic equation of flexible beam in uniform, external, and axial flow. Complex eigenfrequency was calculated by the finite element method. Stability margin of annular cylinder compared to the solid cylinder and change of the dynamic characteristic are presented and discussed as a analysis results.

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소음/진동을 고려한 함포용 Synchro System의 다단 기어 구동장치 개발 (Development of the Multi-Gear Train Devices of Synchro System for the Guns of a Warship which Considered the Noise/Vibration)

  • 이형우;허남수;김인환;이동환
    • Journal of Advanced Marine Engineering and Technology
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    • 제34권8호
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    • pp.1057-1067
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    • 2010
  • 다단 기어연쇄, 베어링, 축, 로터로 구성되는 함포용 synchro system의 구동장치를 개발하기 위하여, AGMA규격에 의한 기어 굽힘강도, 면압강도해석, 기어치형설계를 포함한 정적설계를 수행하였다. 또한 전달행렬법을 효과적으로 적용시킬 수 있는 Hibner's branch법과 자유도가 큰 경우에도 계산 오차 없이 고유특성치를 빠뜨리지 않고 산출할 수 있는 ${\lambda}$-matrix법을 도입하여 함포용 Synchro system의 좌우 선회용과 상하 고각형의 위험속도 해석 및 평가를 하였고, 운전속도 범위 내에 위험속도가 존재하지 않았다.