• Title/Summary/Keyword: SPAR-H

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Handling dependencies among performance shaping factors in SPARH through DEMATEL method

  • Zhihui Xu;Shuwen Shang;Xiaoyan Su;Hong Qian;Xiaolei Pan
    • Nuclear Engineering and Technology
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    • v.55 no.8
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    • pp.2897-2904
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    • 2023
  • The Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method is a widely used method in human reliability analysis (HRA). Performance shaping factors (PSFs) refer to the factors that may influence human performance and are used to adjust nominal human error probabilities (HEPs) in SPAR-H. However, the PSFs are assumed to be independent, which is unrealistic and can lead to unreasonable estimation of HEPs. In this paper, a new method is proposed to handle the dependencies among PSFs in SPAR-H to obtain more reasonable results. Firstly, the dependencies among PSFs are analyzed by using decision-making trial and evaluation laboratory (DEMATEL) method. Then, PSFs are assigned different weights according to their dependent relationships. Finally, multipliers of PSFs are modified based on the relative weights of PSFs. A case study is illustrated that the proposed method is effective in handling the dependent PSFs in SPAR-H, where the duplicate calculations of the dependent part can be reduced. The proposed method can deal with a more general situation that PSFs are dependent, and can provide more reasonable results.

Numerical simulation of dynamic Interactions of an arctic spar with drifting level ice

  • Jang, H.K.;Kang, H.Y.;Kim, M.H.
    • Ocean Systems Engineering
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    • v.6 no.4
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    • pp.345-362
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    • 2016
  • This study aims to develop the numerical method to estimate level ice impact load and investigate the dynamic interaction between an arctic Spar with sloped surface and drifting level ice. When the level ice approaches the downward sloped structure, the interaction can be decomposed into three sequential phases: the breaking phase, when ice contacts the structure and is bent by bending moment; the rotating phase, when the broken ice is submerged and rotated underneath the structure; and the sliding phase, when the submerged broken ice becomes parallel to the sloping surface causing buoyancy-induced fictional forces. In each phase, the analytical formulas are constructed to account for the relevant physics and the results are compared to other existing methods or standards. The time-dependent ice load is coupled with hull-riser-mooring coupled dynamic analysis program. Then, the fully coupled program is applied to a moored arctic Spar with sloped surface with drifting level ice. The occurrence of dynamic resonance between ice load and spar motion causing large mooring tension is demonstrated.

Pitching Motion Analysis of Floating Spar-buoy Wind Turbine of 2MW Direct-drive PMSG (2 MW 영구자석 직접 구동형 부유식 스파 부이 풍력 발전기의 피칭 운동해석)

  • Shin, Pyungho;Kyong, Namho;Choi, Jungchul;Ko, Heesang
    • Journal of the Korean Solar Energy Society
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    • v.37 no.1
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    • pp.1-14
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    • 2017
  • A series of coupled time domain simulations considering stochastic waves and wind based on five 1-h time-domain analyses are performed in normal operating conditions. Power performance and tower base Fore-Aft bending moment and pitching motion response of the floating spar-buoy wind turbine with 2 MW direct-drive PMSG have been analyzed by using HAWC2 that account for aero-hydro-servo-elastic time domain simulations. When the floating spar-buoy wind turbine is tilted in the wind direction, maximum of platform pitching motion is close to $4^{\circ}$. Statistical characteristics of tower base Fore-Aft bending moment of floating spar-buoy wind turbine are compared to that of land-based wind turbine. Maximum of tower base Fore-Aft bending moment of floating spar-buoy wind turbine and land-based wind is 94,448 kNm, 40,560 kNm respectively. This results is due to changes in blade pitch angle resulting from relative motion between wave and movement of the floating spar-buoy wind turbine.

Inhibitory Studies of Scrophulariae Radix on Development of Dermatitis in NC/Nga Mice (현삼(玄蔘)이 NC/Nga mice에서 유발된 피부염에 미치는 영향)

  • Han, Jae-Kyung;Kim, Yun-Hee;Yeo, Eui-Ju
    • The Journal of Pediatrics of Korean Medicine
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    • v.21 no.2
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    • pp.13-34
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    • 2007
  • Objectives The purpose of this study is to examine of the effect of SPAR medicines on the atopy eruption control Methods This experiment is about the expression of IgE, IL-4, IL-6, IL_13, IgM, IgG2a, IgG2b, IgG1 level in serum, and $IFN-{\gamma}$ production by SPAR medicines. We assayed for $CD3e^+/CD69^+$, $CD044^+/CD19^+$ positive cells by flow cytometry in splenocytes and observed the revelation of $CD3e^+/CD69^+$, $CD4^+/CD8^+$, $CD44^+/CD19^+$ marker in PBMC, spleen and DLN. We also observed the outturn of IL-4, IL-5, CCR3, $IFN-{\gamma}$ in skin of a NC/Nga mice. We also analyzed NC/Nga mice's ear and neck-back skin after biopsy and dye by H&E staining method, measured about epidermis and dermis part in comparison with control group. Results SPAR medicines as treatment result to a NC/Nga mice, clinical skin severity score decreased remarkably than the ontrol group. Specially, experiment was results by measuring IgE and IL-6 content in serum 8 weeks, 10 weeks, 12 weeks, 16 weeks, 20 weeks respectively, and it was decreased remarkably than the control group. After experiment ended, the result that observed the revelation CD3e, CD4, CD8, CD19, CD69, CD11a marker in lymph node establishment were observed and that B/T rate becomes recover as normal with political background. In addition to that, the control group was decreased in the measured value of IL-4, IL-5, IL-13, IgM, IgG2a, IgG1's level in serum, and $IFN-{\gamma}$' production secreted in Th1 cell displayed increase by SPAR medicines. IL-4, IL-5, CCR3, and $IFN-{\gamma}$'s gene revelation amount displayed marked decrease than the control group in result that observe effect that get in skin of a NC/Nga dermatitis mouse. Moreover in culture supernatant which cultivate for 14 days after separate skin cell, IL-13 and IL-6 production, and $CD69^+/CD3e^+$, $CD44^+/CD19^+$ expression cell number was decreased than the control group's number. Course inflammation immunocyte permeated of result that effect that SPAR medicines get to NC/Nga mice's skin establishment analyzes ear and neck-back skin after biopsy, and dye by H&E method decreased about epidermis and inflammation of dermis part remarkably than the control group. Conclusions Th1 cell and Th2 cell observe to be shifted by secretion amount of IL-4 and $IFN-{\gamma}$ by SPAR medicines could know that SPAR medicines can be use for treatung allergy autoimmune disease.

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Numerical modeling of internal waves within a coupled analysis framework and their influence on spar platforms

  • Kurup, Nishu V.;Shi, Shan;Jiang, Lei;Kim, M.H.
    • Ocean Systems Engineering
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    • v.5 no.4
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    • pp.261-277
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    • 2015
  • Internal solitary waves occur due to density stratification and are nonlinear in nature. These waves have been observed in many parts of the world including the South China Sea, Andaman Sea and Sulu Sea. Their effect on floating systems has been an emerging field of interest and recent offshore developments in the South China Sea where several offshore oil and gas discoveries are located have confirmed adverse effects including large platform motions and riser system damage. A valid numerical model conforming to the physics of internal waves is implemented in this paper and the effect on a spar platform is studied. The physics of internal waves is modeled by the Korteweg-de Vries (KdV) equation, which has a general solution involving Jacobian elliptical functions. The effects of vertical density stratification are captured by solving the Taylor Goldstein equation. Fully coupled time domain analyses are conducted to estimate the effect of internal waves on a typical truss spar, which is configured to South China Sea development requirements and environmental conditions. The hull, moorings and risers are considered as an integrated system and the platform global motions are analyzed. The study could be useful for future guidance and development of offshore systems in the South China Sea and other areas where the internal wave phenomenon is prominent.

Sloshing characteristics of an annular cylindrical tuned liquid damper for spar-type floating offshore wind turbine

  • Jeon, S.H.;Seo, M.W.;Cho, Y.U.;Park, W.G.;Jeong, W.B.
    • Structural Engineering and Mechanics
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    • v.47 no.3
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    • pp.331-343
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    • 2013
  • The natural sloshing frequencies of annular cylindrical TLD are parametrically investigated by experiment, aiming at the exploration of its successful use for suppressing the structural vibration of spar-type floating wind turbine subject to multidirectional wind, wave and current excitations. Five prototypes of annular cylindrical TLD are defined according to the inner and outer radii of acryl container, and eight different liquid fill heights are experimented for each TLD prototype. The apparent masses near the first and second natural sloshing frequencies are parametrically investigated by measuring the apparent mass of interior liquid sloshing to the acceleration excitation. It is observed from the parametric experiments that the first natural sloshing frequency shows the remarkable change with respect to the liquid fill height for each TLD model with different container dimensions. On the other hand, the second natural sloshing frequency is not sensitive to the liquid fill height but to the gap size, for all the TLD models, convincing that the annular cylindrical sloshing damper can effectively suppress the wave- and wind-induced tilting motion of the spar-type floating wind turbine.

Numerical and experimental study on dynamic response of moored spar-type scale platform for floating offshore wind turbine

  • Choi, E.Y.;Cho, J.R.;Cho, Y.U.;Jeong, W.B.;Lee, S.B.;Hong, S.P.;Chun, H.H.
    • Structural Engineering and Mechanics
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    • v.54 no.5
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    • pp.909-922
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    • 2015
  • The dynamic response and the mooring line tension of a 1/75 scale model of spar-type platform for 2.5 MW floating offshore wind turbine subject to one-dimensional regular harmonic wave are investigated numerically and verified by experiment. The upper part of wind turbine which is composed of three rotor blades, hub and nacelle is modeled as a lumped mass the scale model and three mooring lines are pre-tensioned by means of linear springs. The coupled fluid-rigid body interaction is numerically simulated by a coupled FEM-cable dynamics code, while the experiment is performed in a wave tank with the specially-designed vision and data acquisition system. The time responses of surge, heave and pitch motions of the scale platform and the mooring line tensions are obtained numerically and the frequency domain-converted RAOs are compared with the experiment.

A Study of Flutter Analysis for the Composite Box Wings with Various Laminates (다양한 적층각에 대한 상자형 복합재료 날개의 플러터 특성연구)

  • Chung, Y.H.;Kwon, H.J.;Kim, D.H.;Lee, I.;Kim, C.G.
    • Composites Research
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    • v.15 no.1
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    • pp.1-8
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    • 2002
  • In this study, the flutter analysis for a rectangular box wing and an actual fighter wing with composite shin, aluminum spar and aluminum rib has been conducted. A conservative 3D wing-box model of an actual wing is modeled by MSC/PATRAN and the corresponding free vibration analysis has been performed by MSC/NASTRAN. The finite elements of membrane, rod and shear panel are used. Using the practical ply angles, various composite laminates are composed and analysed. The DLM code which is linear aerodynamic theory in frequency domain is applied to calculate unsteady aerodynamic pressure in subsonic flow region and the V-g and p-k methods are applied to obtain the solution of aeroelastic governing equation in frequency domain.

Studios on the Synthetic Pheromones of Striped Rice Borer and Tortricid Insect Pests (이화명충과 과수잎말이나방류 해충의 합성 Pheromone에 관한 연구)

  • Song Y. H.;Song H. Y.;Kim H. K.;Chang Y. D.;Lippold P. C.
    • Korean journal of applied entomology
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    • v.17 no.1 s.34
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    • pp.41-47
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    • 1978
  • Pheromones of several insect species were evaluated in a screening program in terms of their usefulness in pest forecasting and control in Korea. Species included striped rite borer (Chilo suppressalis) and tortricid moths, which attack deciduous fruit, and colding moth. The pheromone of striped rice borer was supplied through the courtesy of the Tropical Products Institute, London. Pheromones of other species were obtained from Cornell University and the Zoecon Corporation of Palo Alto, California. 'rho results of this experiment were as follows: 1. Live traps containing virgin striped rice borer female moths were more effective in attracting male moths than were the pheromone traps. 2. Since the effectiveness of the striped rice borer pheromone decreased dramatically with time, it was difficult to estimate the peak tine of the borer emergence. 3. The primary species trapped in deciduous fruit orchards was the oriental fruit moth, Grapholitha molesta. The traps were baited with the phermones, OFM and LAW. 4. Several moth species were trapped with OBLR. RBLR. SPAR and ArcM phermones but few were trapped with the remaining eight tortricid pheromones. 5. The following tortricid pheromones might be useful for forecasting the species given: OFM, LAW : Grapholitha molesta OBLR : Archips breviprecanus OBLH, RBLR, ArcM : Archippus coreensis Archips fuscocupreanus Hoshinoa longicellana SPAR, TBM ; Phyroderces sp.

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