• 제목/요약/키워드: Dependent

검색결과 29,487건 처리시간 0.054초

Parametric study for buildings with combined displacement-dependent and velocity-dependent energy dissipation devices

  • Pong, W.S.;Tsai, C.S.;Chen, Ching-Shyang;Chen, Kuei-Chi
    • Structural Engineering and Mechanics
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    • 제14권1호
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    • pp.85-98
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    • 2002
  • The use of supplemental damping to dissipate seismic energy is one of the most economical and effective ways to mitigate the effects of earthquakes on structures. Both displacement-dependent and velocity-dependent devices dissipate earthquake-induced energy effectively. Combining displacement-dependent and velocity-dependent devices for seismic mitigation of structures minimizes the shortcomings of individual dampers, and is the most economical solution for seismic mitigation. However, there are few publications related to the optimum distributions of combined devices in a multiple-bay frame building. In this paper, the effectiveness of a building consisting of multiple bags equipped with combined displacement-dependent and velocity-dependent devices is investigated. A four-story building with six bays was selected as an example to examine the efficiency of the proposed combination methods. The parametric study shows that appropriate arrangements of different kinds of devices make the devices more efficient and economical.

THE STRONG LAWS OF LARGE NUMBERS FOR WEIGHTED SUMS OF PAIRWISE QUADRANT DEPENDENT RANDOM VARIABLES

  • Kim, Tae-Sung;Baek, Jong-Il
    • 대한수학회지
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    • 제36권1호
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    • pp.37-49
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    • 1999
  • We derive the almost sure convergence for weighted sums of random variables which are either pairwise positive quadrant dependent or pairwise positive quadrant dependent or pairwise negative quadrant dependent and then apply this result to obtain the almost sure convergence of weighted averages. e also extend some results on the strong law of large numbers for pairwise independent identically distributed random variables established in Petrov to the weighted sums of pairwise negative quadrant dependent random variables.

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Endothelium-dependent Contraction of Aorta in One-kidney, One-clip Goldblatt Hypertensive Rat

  • Jeon, Byeong-Hwa;Lee, Kug-Hee;Kim, Hoe-Suk;Kim, Se-Hoon;Chang, Seok-Jong
    • The Korean Journal of Physiology
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    • 제30권2호
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    • pp.269-278
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    • 1996
  • The mechanism of impaired endothelium-dependent relaxation in the aorta of one-kidney, one clip Goldblatt hypertensive (1K,1C-GBH) rats was investigated. 8 week-old Wistar-Kyoto (WKY) rats were made hypertensive by left renal artery stenosis with contralateral nephrectomy. Endothelium-dependent relaxation was significantly reduced in 1K,1C-GBH rats as compared with WKY rats. However, the relaxation by sodium nitroprusside in 1K,1C-GBH rats was not reduced as compared with WKY rats. The impairment of endothelium-dependent relaxation in 1K,1C-GBH rats was partially restored by the pretreatment of indomethacin or SQ29548. When the nitric oxide production was inhibited by L-nitroarginine methyl ester, acetylcholine (ACh) induced a endothelium-dependent contraction that was greater in 1K,1C-GBH rats than in WKY rats. Endothelium-dependent contraction by ACh was completely abolished by indomethacin or SQ29548. However, imidazole, tranylcypromine and superoxide dismutase did not affect the endothelium-dependent contraction in 1K,1C-GBH rats. These results suggest that impaired endothelium-dependent relaxation in the 1K,1C-GBH rats might be due to the simultaneous release of EDCF, and that prostaglandin B2 may be involved as a mediator of endothelium-dependent contraction.

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판재의 성형한계 결정을 위한 시간의존적 방법의 제안 (Proposal of a Time-dependent Method for Determining the Forming Limit of Sheet Metal)

  • 김성곤;김형종
    • 소성∙가공
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    • 제27권2호
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    • pp.115-122
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    • 2018
  • Most domestic and international standards on the forming limit diagram (FLD) including ISO 12004-2, use a 'position-dependent method,' which determines the forming limit from a strain distribution measured on the specimen after necking or fracture. However, the position-dependent method has inherent problems such as the incidence of asymmetry of a strain distribution, the estimation of missing data near fracture, the termination time of test, and the deformation due to the new stress equilibrium after a fracture, which is blamed for causing sometimes a significant lab-to-lab variation. The 'time-dependent method,' which is anticipated to be a new international standard for evaluating the forming limit, is expected to greatly improve these intrinsic disadvantages of the position-dependent method. It is because the time-dependent method makes it possible to identify and accurately determine the forming limit, just before the necking point from the strain data as continuously measured in a short time interval. In this study, we propose a new time-dependent method based on a Gaussian fitting of strain acceleration with the introduction of 'normalized correlation coefficient.' It has been shown in this study that this method can determine the forming limit very stably and gives a higher value, which is in comparison with the results of the previously studied position-dependent and time-dependent methods.

Delay-Dependent Control for Time-Delayed T-S Fuzzy Systems Using Descriptor Representation

  • Jeung, Eun-Tae;Oh, Do-Chang;Park, Hong-Bae
    • International Journal of Control, Automation, and Systems
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    • 제2권2호
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    • pp.182-188
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    • 2004
  • This paper presents a design method of delay-dependent control for T-S fuzzy systems with time delays. Based on parallel distributed compensation (PDC) and a descriptor model transformation of the system, a delay-dependent control is utilized. An appropriate Lyapunov-Krasovskii functional is chosen for delay-dependent stability analysis. A sufficient condition for delay-dependent control is represented in terms of linear matrix inequalities (LMIs).

From the Absorption Profile to the Potential by a Time-dependent Inversion Method

  • 김화중;김영식
    • Bulletin of the Korean Chemical Society
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    • 제18권12호
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    • pp.1281-1285
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    • 1997
  • The time-dependent tracking inversion method is developed to extract the potential of the excited state from frequency-domain measurements, such as the absorption profile. Based on the relay of the regularized inversion procedure and time-dependent wave-packet propagation, the algorithm extract the underlying potential piece by piece by tracking the time-dependent data which can be synthesized from frequency-domain measurements. We have demonstrated the algorithm to extract the potential of excited state for a model diatomic molecule. Finally, we describe the merits of the time-dependent tracking inversion method compared to the time-dependent inversion and discuss several extensions of the algorithm.

A novel model of a nonlocal porous thermoelastic solid with temperature-dependent properties using an eigenvalue approach

  • Samia M. Said
    • Geomechanics and Engineering
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    • 제32권2호
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    • pp.137-144
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    • 2023
  • The current article studied wave propagation in a nonlocal porous thermoelastic half-space with temperature-dependent properties. The problem is solved in the context of the Green-Lindsay theory (G-L) and the Lord- Shulman theory (L-S) based on thermoelasticity with memory-dependent derivatives. The governing equations of the porous thermoelastic solid are solved using normal mode analysis with an eigenvalue approach. In order to illustrate the analytical developments, the numerical solution is carried out, and the effect of local parameter and temperature-dependent properties on the physical fields are presented graphically.

SUS304강의 사이클의존형에서 시간의존형균열성장으로의 천이에 관한 연구 (A Study on Transition From Cycle-dependent to Time-dependent Crack Growth in SUS304 Stainless Steel)

  • 주원식;조석수
    • Journal of Welding and Joining
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    • 제14권1호
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    • pp.38-46
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    • 1996
  • High temperature low cycle fatigue crack growth behavior is investigated over a range of two temperatures and various frequencies in SUS 304 stainless steel. It is found that low frequency and temperature can enhance time-dependent crack growth. With high temperature, low frequency and long crack length, ${\Delta}J_c/{\Delta}J_ f$, the ratio of creep J integral range to fatigue J integral range is increased and time-dependent crack growth is accelerated. Interaction between ${\Delta}J_f$ and ${\Delta}J_c$ is occured at high frequency and low temparature and ${\Delta}J_c$, creep J integral range is fracture mechanical parameter on transition from cycle-dependent to time dependent crack growth in creep temperature region.

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편측성 폐질환 환자의 체위변경이 생리적 지표에 미치는 영향 (The Effect of Body Positioning on Physiologic Index in Patients with Unilateral Lung Disease)

  • 조지연;이향련
    • 성인간호학회지
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    • 제12권1호
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    • pp.122-133
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    • 2000
  • The purpose of this study was to identify the effect of body positioning on $PaO_2$, $SpO_2$, systolic blood pressure, diastolic blood pressure, pulse, and respiration(above all defined physiologic index), of patients with unilateral lung disease. The subjects for this study were eleven patients admitted to I.C.U. of K.H.M.C. with a diagnosis of unilateral lung disease confirmed by chest X-ray and the attending doctor, from January 30th. to April 20th. 1999. A quasi-experimental repeated-measures cross-over design was used to compare three body positions(semi-Fowler's, lateral decubitus with good lung dependent, and lateral decubitus with diseased lung dependent). Each subject spent 30 minutes in semi-Fowler's position and 2 hours in good lung dependent position and diseased lung dependent position. Starting in the semi-Fowler's position, then in the lateral position with the good lung dependent or the diseased lung dependent as assigned in random order. Thirty minutes after each positioning, arterial blood sample was analyzed. Measurements of all physiologic index were recorded at the specified intervals(0, 30, 60 90, and 120 minutes) in good lung dependent and diseased lung dependent position. Statistical comparison of $PaO_2$ value was done using the Wilcoxon Signed Rank Test, and Multivariate repeated-measures analysis of variance was performed to analyse the within-subject effect of two dependent position for 2 hours on the five dependent variables: (1) $PaO_2$ (2) $SpO_2$ (3) systolic blood pressure (4) diastolic blood pressure (5) pulse. The results obtained were as follows: 1. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the diseased lung dependent position(Z=-2.8451, p=.002). 2. The $PaO_2$ value in the good lung dependent position was significantly higher than the $PaO_2$ value in the semi-Fowler's position (Z=-2.6673, p=.003). 3. The difference between the $PaO_2$ value in the semi-Fowler's position and the $PaO_2$ value in the diseased lung dependent position was not significant(Z=-1.2448, p=.10). 4. There were no statistically significance in the trends of physiologic index in the good lung dependent position and the diseased lung dependent position. From the results, it may be concluded that the good lung dependent position is the most effective position for patients with unilateral lung disease that improve oxygenation. Identification of positioning over time may be need further studies.

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SUS 304鋼 의 크리이프 溫度領域 에 관한 時間依存型 및 사이클依存型 疲勞크랙 傳播 의 遷移 (Transition from Cycle-Dependent to Time-Dependent Fatigue Crack Propagation at Creep Temperature of SUS 304 Steel)

  • 유헌일;주원식
    • 대한기계학회논문집
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    • 제9권5호
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    • pp.539-547
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    • 1985
  • 본 논문에서는 이상과 같은 연구현상을 배경으로 응력비 R.geq.0인 사인응력파 에서도 사이클의존형 크랙전파가 공존하는가, 공존한다면 그 전이를 결정짓는 조건을 구하기 위해, 대표적인 고온용 재료인 SUS 304강을 이용하여 온도 650.deg. C, 대기중에서 반복속도 .nu., 응력비 R, 응력레벨 .sigma.$_{maxo}$등의 실험조건을 바꾸어 고온저사이클 피로실험을 하였다. 또 이 현상의 기초과정을 이해하는데 도움을 주기 위하여 파면 관찰을 행하였다.