• 제목/요약/키워드: span length

검색결과 795건 처리시간 0.02초

노화와 수명에 관한 사상의학적 양생관에 대한 고찰 (A study of Aging and Life Span in Sasang Constitutional Medicine)

  • 이의주;송일병;고병희;유정희
    • 사상체질의학회지
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    • 제14권3호
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    • pp.7-16
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    • 2002
  • Purpose The goal of this study tried to provide aging and life span in Sasang Constitutional Medicine. Methods It was researched Master Dong-Mu's documentary records about aging and the life span represented by ${\ulcorner}$Dongyi Soose Bowon Sasang Chobongyun${\lrcorner}$ and ${\ulcorner}$Dongyi Soose Bowon${\lrcorner}$ published in 1901. Results & conclusion 1. A principal of regimen according to Sasang Constitutional Medicine isn't medicational method but non-medicational method. There are control mind and upright oneself. 2. Dong-Mu's the views of the span of life represented by 'Inherent vitality' that a term means health promoting and forecasting length of the life. He also emphasizied a natural power of recovery from damaged vitality. 3. Greed is reduced one's lifetime. It is originated by bias for 'joy-anger -sorrow-pleasure'. The other example is 'Liquor-Sex-Property- Authority'. 4. The way of prolonging lifetime what managed small visceral intestines through constitutional upright oneself. This is found on pathology, care of health and constitutional 'Knowledge and Deed'.

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Compensation Characteristics Dependence on the Position of Optical Phase Conjugator in 320 Gbps WDM System

  • Lee Seong-Real;Yim Hwang-Bin
    • Journal of electromagnetic engineering and science
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    • 제4권4호
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    • pp.162-167
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    • 2004
  • In this paper, optimal position of optical phase conjugator(OPC) for best compensating distorted WDM channels due to both chromatic dispersion and self phase modulation(SPM) is numerically investigated, and the compensation characteristics of overall WDM channels at this position is investigated, comparing with that in case of OPC placed at mid-way of total transmission length. It is confirmed that the compensation extents in WDM system with OPC is more improved by the shifting OPC position from the mid-way of total transmission length. And, we confirmed that the optimal position of OPC must be selected to the position decreasing not only eye opening penalty(EOP) of overall WDM channels but also EOP deviation between WDM channels, and this OPC position should be altered as various system parameters such as modulation format, and fiber dispersion, etc. Using proposed configuration, it is possible to remove all in-line dispersion compensator, reducing span losses and system costs.

철도차량용 차체틸팅기구의 기구학적 특성연구 (The Study on the Kinematics of Carbody Tilting Mechanism for Railway Vehicles)

  • 김정석;김남포;고태환
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.384-388
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    • 2004
  • This study presents parametric studies for design of tiling mechanism to be used in 180km/h tilting train. The titling mechanism is composed of 4 links, a tilting bolster and an electro-mechanical actuator. First we have determined the installation height of tilting actuator using 3D tilting bogie modeling. Secondary, we verified movements of the tiling center and train body CG along variation of upper and lower span length. From this study, we obtained the upper and lower span length to minimize the lateral and vertical motion of CG of train body. Finally, we evaluated the tilting actuator force and power required to tilt the train body to $\pm$8$^{\circ}$.

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Measurement of the mixed mode fracture strength of green sandstone using three-point bending specimens

  • Li, Yifan;Dong, Shiming;Pavier, Martyn J.
    • Geomechanics and Engineering
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    • 제20권1호
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    • pp.9-18
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    • 2020
  • Three-point bending specimens have been used to investigate the mixed mode fracture of green sandstone. Dimensionless stress intensity factors and T-stresses were calculated first by using the finite element method for various crack lengths, crack angles and span to length ratios. It is shown that three-point bending specimens can provide the whole range of mode mixities from pure mode I to pure mode II, provided suitable values are chosen for the crack angle and span to length ratio. The fracture test results were also used to compare with predictions of different criteria. These comparisons show that modified criteria including the influence of the T-stress agree better with experiment than the conventional criteria but that no one criterion matches perfectly the test results.

산업용 컨버팅 머신의 펜듈럼 덴서 모델링 및 해석 (Modeling and Analysis of a Pendulum Dancer in Industrial Converting Machines)

  • 강현규;신기현;김상철
    • 대한기계학회논문집A
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    • 제33권5호
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    • pp.482-488
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    • 2009
  • Dancer system is typically used equipment for attenuation of tension disturbances. In industrial converting machines, a composite type of dancer system is applied which is mixture of active and passive dancer. It includes feedback position control loop of roll with pendulum dancer and its characteristics is different from passive and active one. In this paper, a mathematical model of the pendulum dancer was derived including PI position feedback controller and it was analyzed by using a pole-zero map and bode plot under various conditions. It was found out that velocity, length of span and inertia were associated with the performance of regulation. It was suggested that the length of upstream span should be greater than that of the downstream and the inertia should be smaller for improvement of the performance. The results can be used for design guidelines of the industrial dancer system.

교량의 충격계수에 관한 연구 (A Study on the Impact Factor of Bridges)

  • 윤일로;류택은
    • 한국산업융합학회 논문집
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    • 제7권2호
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    • pp.161-166
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    • 2004
  • The impact factor of bridges is analyzed based on experimental data to examine the characteristics of the dynamic responses of bridges. The experimental impact factors are compared with the impact factor of Korean Highway Design Specification and Japan T-load in terms of the span length. According to the superstructural types of bridges, the variation of the impact factor is analyzed. When vehicles are passing on a bridge, the dynamic effect acts on the bridge impact factor more than at the time of design because of the velocity of vehicles, the surface roughness reduction due to the deterioration of the bridge deck pavement, and the disconnection of the bridge entrance and the expansion joint. Because the actual value is greater than the expected value at the time of design, the dynamic response of the bridge accelerates the deterioration of the bridge due to the accumulation of fatigue, and the bridge's life-time is shortened and can have an influence on the serviceability and safety of the bridge.

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장대레일이 설치된 교량에서의 축방향 변위 및 축력 변화 연구 (A Study of Longitudinal Forces and Displacements in a Multi-Span Bridge Equipped with a CWR Track)

  • 이주헌;허영
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 춘계학술대회 논문집
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    • pp.442-449
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    • 1999
  • Due to temperature variations, considerable longitudinal rail forces and displacements may develop in continuous welded rail(CWR) track on long-span bridges or viaducts. Excessive relative displacements between sleepers and ballast bed may disturb the stable position of the track in the ballast which results in a lower frictional resistance. Generally, these problems are solved by installing rail expansion devices. However the application of expansion devices in high-speed tracks on existing bridges, as a means to prevent excessive longitudinal displacements and forces, is not attractive method due to comfort, safety and maintenance aspects. An alternative and very effective solution is possibly the use of so-called zero longitudinal restraint(ZLR) fastenings over some length of the track. The calculations, carried out in this respect, show a considerable reduction of track displacements, track forces, and the relative sleeper/ballast displacements. This reduction depends on the length over which these fastenings are installed. In this paper calculations of the longitudinal displacments and forces in a CWR track and substructure resulting from thermal, mechanical and kinematical loads were carried out using the FEM analysis program LUSAS

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국내 저층 콘크리트 골조의 초과강도 (Seismic Overstrength of Low-rised RC Frame in Korea)

  • 이영욱
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
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    • pp.28-35
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    • 1998
  • The seismic overstrength factor $\Omega$ is evaluated for 4-story reinforced concrete buildings in Korea(of which seismic intensity is low). The study model is designed according to aseismic guideline research - phase II in Korea. The effect of variation of span length and bay number, dead load is considered, especially including the variation of hardening ration after yielding. And push-over analysis is performed, in which the external and internal frame is connected by rigid-link and the $\Omega$ is calculated using the roof drift ratio at 2%. For Zone I, the mean value of $\Omega$ is ranged form 2.3 to 2.5, For Zone II, from 3.1 to 3.4. For low hardening ratio(3%) after yielding, $\Omega$ has little relations with the number of bay, like as the results of other research. But for 5% hardening ratio, $\Omega$ is increased as the number of bay is increased. Within general gravity-load bound, the variation of D.L. has variation of D. L. has no effect on $\Omega$. And, $\Omega$ is increased as the span length is increased.

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강철도교 피로평가 시스템 개발 및 검증 (Test and Development of Fatigue Assesement System for Steel Railway Bridges)

  • 경갑수;최일윤;이준석;김이현;박진우
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.185-190
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    • 2005
  • In order to evaluate that factors such as span length, member type and train loading affected on fatigue of steel railway bridges, in this paper, a series of field tests were carried out for some plate girder bridges. From the result estimated by rainflow counting method to analyze real strain-time curve obtained from the field test, it was known that the fatigue effect is more significant in the bridges having short span length and the secondary members regardless of train load types.

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On the fundamental period of infilled RC frame buildings

  • Asteris, Panagiotis G.;Repapis, Constantinos C.;Cavaleri, Liborio;Sarhosis, Vasilis;Athanasopoulou, Adamantia
    • Structural Engineering and Mechanics
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    • 제54권6호
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    • pp.1175-1200
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    • 2015
  • This paper investigates the fundamental period of vibration of RC buildings by means of finite element macro-modelling and modal eigenvalue analysis. As a base study, a number of 14-storey RC buildings have been considered "according to code designed" and "according to code non-designed". Several parameters have been studied including the number of spans; the span length in the direction of motion; the stiffness of the infills; the percentage openings of the infills and; the location of the soft storeys. The computed values of the fundamental period are compared against those obtained from seismic code and equations proposed by various researchers in the literature. From the analysis of the results it has been found that the span length, the stiffness of the infill wall panels and the location of the soft storeys are crucial parameters influencing the fundamental period of RC buildings.