• 제목/요약/키워드: strong stability

검색결과 802건 처리시간 0.033초

Investigation on mechanics performance of cable-stayed-suspension hybrid bridges

  • Zhang, Xin-Jun
    • Wind and Structures
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    • 제10권6호
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    • pp.533-542
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    • 2007
  • The cable-stayed-suspension hybrid bridge is a cooperative system of the cable-stayed bridge and suspension bridge, and takes some advantages and also makes up some deficiencies of both the two bridge systems, and therefore becomes strong in spanning. By taking the cable-stayed-suspension hybrid bridge, suspension bridge and cable-stayed bridge with main span of 1400 m as examples, the mechanics performance including the static and dynamic characteristics, the aerostatic and aerodynamic stability etc is investigated by 3D nonlinear analysis. The results show that as compared to the suspension bridge and cable-stayed bridge, the cable-stayed-suspension hybrid bridge has greater structural stiffness, less internal forces and better wind stability, and is favorable to be used in super long-span bridges.

고도수처리 환경에 노출된 에폭시 수지계 방수/방식재의 침식 저항성 평가에 관한 실험적 연구 (An Experimental Study on the Deteriorative Resistance of Epoxy Resin Waterproofing Phase under Advanced Water and Wastewater Treatment)

  • 오상근;장성주;김영삼;양승도
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2002년도 학술.기술논문발표회
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    • pp.59-62
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    • 2002
  • Recently, advanced system for water and wastewater treatment is introduced and operated because of water pollution and etc. One of this System makes use of O3(Ozone) for water and wastewater treatment. In airtight concrete structure, waterproofing phase as well as water are affected by strong oxidative O3 in the long-term. For this reason, material stability against O3 is examined. Consequently, the purpose of this study is to find out material stability an object of epoxy resin by way of accelerated O3 testing.

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STOCHASTIC DIFFERENTIAL EQUATION MODELS FOR EXTRACELLULAR SIGNAL-REGULATED KINASE PATHWAYS

  • Choo, S.M.;Kim, Y.H.
    • Journal of applied mathematics & informatics
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    • 제31권3_4호
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    • pp.457-467
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    • 2013
  • There exist many deterministic models for signaling pathways in systems biology. However the models do not consider the stochastic properties of the pathways, which means the models fit well with experimental data in certain situations but poorly in others. Incorporating stochasticity into deterministic models is one way to handle this problem. In this paper the way is used to produce stochastic models based on the deterministic differential equations for the published extracellular signal-regulated kinase (ERK) pathway. We consider strong convergence and stability of the numerical approximations for the stochastic models.

공기 역학적으로 가진 되는 헬름홀쯔 공명기에서 발생하는 소음에 관한 예측모델 (A Predictive Model for the Tones Generated from Aerodynamically Excited Helmholtz Resonators)

  • 국형석
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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    • pp.478-485
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    • 1998
  • The interior of open cavities exposed to a grazing flow is known to experience, strong periodic pressure, oscillations sustained for a wide range of flow velocities. In this study, an original approach was followed to develop a describing function model for the flow-excitation mechanism, governed by the shedding of discrete vortices within the shear layer over the orifice. A feedback loop analysis was performed to predict the frequency and the amplitude of the interior pressure fluctuations. Furthermore, a limit cycle stability analysis based on the extended Nyquist Stability criterion allowed the predictions of the onset and termination velocities for various modes. The analytical model was verified experimentally.

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마찰재에 사용되는 지르콘($ZrSiO_4$) 입자의 크기에 따른 마찰특성 (Tribological Behavior of Automotive Brake Pads with Different Sizes of zircon Particles)

  • 홍영석;고길주;박상진;장호
    • Tribology and Lubricants
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    • 제18권3호
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    • pp.204-210
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    • 2002
  • Automotive brake pads with four different sizes of zircon particles (average sizes of 1㎛, 6㎛, 75㎛, and 140㎛, respectively) were investigated to evaluate the size effect of abrasive particles on friction performance. Results showed that the brake pads with the larger size of zircon particles tend to show better frictional stability and low pad wear. However, the rotor surface was severely abraded in the case of using larger zircon particles. On the other hand, the small zircon particles in the pads showed the fast increase of the coefficient of friction with friction force oscillation and the tendency was pronounced at low sliding speeds. The brake pads with small particle sizes also exhibited strong fade phenomena at elevated temperatures.

초고용량 양방향 말뚝재하시험(BDH PLT) 수행사례 분석 (A Case Study of High Capacity Bi-Directional High Pressure Pile Load Test)

  • 김상일;이민희;정성민;정은택;최용규
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.1156-1163
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    • 2010
  • The bi-directional high pile load test(BDH PLT) does not have weaknesses found in the existing bi-directional low pile load test(BDL PLT); it has strong economics, is unbound by load capacity limit and secures quality stability of working piles. In this study, Verification the field found a very high capacity level of stability and reliability of the BDH PLT, as well as outstanding field applicability. Field verifications reaffirmed the advantage of the BDH PLT device, which was capable of loading 90 MN capacities as maximum. It was also found to be durable enough to load high capacity with ease.

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오존 정수처리 음용수조 구조물에 사용하는 에폭시 수지 방수.방식재의 표면특성 평가 (A Study on the Surface Deterioration Evaluation of Epoxy Resin Coating as Anticorrosive Material of Concrete Water Tank Using Ozone($O_3$))

  • 오상근;강효진;곽규성
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.513-518
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    • 2003
  • Recently, advanced systems for water treatment are introduced for water quality improvement. One of those systems is water treatment method using ozone($O_3$). For it has strong oxidizing energy, it is necessary to have materisl stability against $O_3$. In this paper, epoxy resin specimens using as anticorrosive material of concrete structure for drink water are used to serve as a material of deterioration evaluation. It is to be studied weight loss, surface corrosion of specimens, ingredient analysis of floating particle, a solute of chemical ingredient by way of accelerated ozone testing. As the results of experiment, specimen weight is decreased. The surface of specimen is eroded heavily and showed a loss of gloss and floating particle, and in the stability for drinking water, harmful ingredient is not detected in the water.

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PEMFC 연료전지의 과도현상 특성 (Dynamic Transient Phenomena of a Proton Exchange Membrane Fuel Cells)

  • 이영;최용성;장우새;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.203-203
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    • 2010
  • The proton exchange membrane fuel cell (PEMFC) is different from the normal power supply, and it is a nonlinear, multi-input, strong coupling, the complex dynamic system with large time delay. At present, many studies on the content of the fuel cell fuel cells focus on a static process, this paper analyzed in subsequent sections of the process of fuel cell dynamic response time of transition, and then it found the method to reduce the response time during the process of load change to ensure that the stability of output power.

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Effect of Germination and Heating on Phytase Activity in Cereal Seeds

  • Ma, Xi;Shan, Anshan
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권7호
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    • pp.1036-1039
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    • 2002
  • The effect of germination on phytase activity in wheat NEAU123, triticale5305 and rye2 was studied in the present study. Germination significantly increased phytase activity by 2.04 times for wheat NEAU123 (3 d), 1.82 times for triticale 5305 (1 d) and 2.45 times for rye2 (1 d), respectively. It was safe for phytase in fresh malts kilned for 2 h at $40^{\circ}C$. Phytase in cereal seeds had strong heat stability. There was no loss of phytase activity in cereal seeds heated at $70^{\circ}C$ for 1 h, a little loss (${\leq}$5.46%) at $80^{\circ}C$ or $90^{\circ}C$. Even heated at $100^{\circ}C$, the phytase activity in wheat NEAU123, triticale5305 and rye2 remained 89.47%, 86.44% and 104.64%, respectively.

자기부상열차 UTM-01의 부상 공극 해석 (Air Gap Responses of the Maglev Vehicle UTM-01 to Irregularities of Guideway)

  • 한형석;김숙희;임봉혁;권정일;허영철
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.291-295
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    • 2007
  • The irregularities in the guideways used in the Maglev transportation system that result from surface roughness and deflection of guideway have strong effects on the dynamic characteristics of Maglev vehicles, because the electromagnetic suspension of Maglev vehicles strongly interacts with the guideway. For this reason, a numerical prediction of air gap responses to these irregularities is desirable to improve aspects of running performance, such as stability and passenger comfort, while minimizing aesthetic impact and construction cost. This paper presents a procedure to predict the air gap response which is a criteria for stability, and investigates the responses with the goal of attaining higher travel speeds in the urban Maglev vehicle UTM-01 utilizing electromagnetic suspension.

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