• Title/Summary/Keyword: redistribution

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Communication Schedule for GEN_BLOCK Redistribution (GEN_BLOCK간 재분산을 위한 통신 스케줄)

  • Yook, Hyun-Gyoo;Park, Myong-Soon
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.5
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    • pp.450-463
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    • 2000
  • Array redistribution is usually required to enhance algorithm performance in many parallel programs on distributed memory multicomputers. GEN_BLOCK redistribution, which is redistribution between different GEN_BLOCKs, is essential for load balancing. However, prior research on redistribution has been focused on regular redistribution, such as redistribution between different CYCLIC(N)s. GEN_BLOCK redistribution is very different from regular redistribution. Message passing in regular redistribution involves repetitions of basic message passing patterns, while message passing for GEN_BLOCK redistribution shows locality. This paper proves that two optimal condition, reducing the number of communication steps and minimizing redistribution size, are essential in GEN_BLOCK redistribution. Additionally, by adding a relocation phase to list scheduling, we make an optimal scheduling algorithm for GEN_BLOCK redistribution. To evaluate the performance of the algorithm, we have performed experiments on a CRAY T3E. According to the experiments, it was proven that the scheduling algorithm shows better performance and that the conditions are critical in enhancing the communication speed of GEN_BLOCK redistribution.

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Two Level-Parallel Type Inventory Systems with Backorder and Redistribution (사후주문과 재분배를 고려한 2수준 재고시스템)

  • 권희철
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.17 no.32
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    • pp.113-120
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    • 1994
  • This study presents a two level-parallel type inventory systems with one upper level facility in the first echelon and n-lower level facilities in the second echelon. The stocks at the lowest facilities can become unbalanced with the random variations in the demands. This paper deals with the imbalance by considering redistribution and backorder. The system with redistribution and the system with backorder and redistribution are analized. The comparison of two cases shows that the system with redistribution and backorder gives smaller stocks than the system with redistribution.

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Modeling of Irradiation Temperatures and Constituent Redistribution in U-10Zr Metallic Fuel

  • Nam, Cheol;Hwang, Woan
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05b
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    • pp.207-213
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    • 1997
  • The computational scheme on a irradiation temperature of U-10Zr fuel was established considering porosity formation, bond sodium infiltration and constituent redistribution. Thermotransport theory was adapted to model the redistribution phenomenon. As a results, the bond sodium seems to be logged in the outer region of fuel slug. The main driving force for constituent redistribution appears to be the Zr solubility change along to radial position of the fuel. It is evident that the heat of transport also has some contribution to the redistribution.

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Probabilistic models for curvature ductility and moment redistribution of RC beams

  • Baji, Hassan;Ronagh, Hamid Reza
    • Computers and Concrete
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    • v.16 no.2
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    • pp.191-207
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    • 2015
  • It is generally accepted that, in the interest of safety, it is essential to provide a minimum level of flexural ductility, which will allow energy dissipation and moment redistribution as required. If one wishes to be uniformly conservative across all of the design variables, curvature ductility and moment redistribution factor should be calculated using a probabilistic method, as is the case for other design parameters in reinforced concrete mechanics. In this study, simple expressions are derived for the evaluation of curvature ductility and moment redistribution factor, based on the concept of demand and capacity rotation. Probabilistic models are then derived for both the curvature ductility and the moment redistribution factor, by means of central limit theorem and through taking advantage of the specific behaviour of moment redistribution factor as a function of curvature ductility and plastic hinge length. The Monte Carlo Simulation (MCS) method is used to check and verify the results of the proposed method. Although some minor simplifications are made in the proposed method, there is a very good agreement between the MCS and the proposed method. The proposed method could be used in any future probabilistic evaluation of curvature ductility and moment redistribution factors.

Analytical Study on the Flexural Moment Redistribution of Continuous Reinforced Concrete Beams (철근콘크리트 연속보의 휨모멘트 재분배에 관한 해석적 연구)

  • Cheon, Ju-Hyun;Seong, Dae-Jeong;Lee, Sang-Cheol;Shin, Hyun-Mock
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.385-388
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    • 2006
  • The purpose of this study is to offer an appropriate method of the degree of the flexural moment redistribution for continuous reinforced concrete beams. Twenty-four two-span continuous beams were selected to determine the manner and degree of moment redistribution. The concept of ductility is linked to the moment redistribution capacity and, consequently, the safety of the structure. Knowledge of the plastic rotation capacity of plastic regions of the structure is important for a plastic analysis or a linear analysis with moment redistribution. A nonlinear finite element analysis program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used to evaluate the ultimate strength and degree of moment redistribution. The nonlinear material model for the reinforced concrete is composed of models for characterizing the behavior of the concrete, in addition to a model for characterizing the reinforcing bars.

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An experiment of two span reinforced and prestressed concrete beams for the ductile behavior (철근 및 프리스트레스콘크리트 2경간 연속보의 연성거동에 관한 실험)

  • Lee, Sang-Woo;Kim, Jung-Koo;Oh, Seung-Hyun;Kang, Won-Ho
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.393-396
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    • 2006
  • One of the important aspects of ductility is redistribution. To see the difference of redistribution between reinforced concrete members and prestressed concrete beams, two span continuous concrete beams are tested. From the test results, we can get important information on the redistribution ratio. After occurrence of crack at support section, the redistribution ratio increased and after yielding they fluctated very much. Compare with reinforced concrete, the redistribution ratio of prestressed concrete beam changed more abruptly after yielding. Both of the them show limited redistribution up to 70%.

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A Calculation Model for Fuel Constituent Redistribution and Temperature Distribution on Metallic U-10Zr Fuel Slug of Liquid Metal Reactors

  • Nam, Cheol;Hwang, Woan
    • Nuclear Engineering and Technology
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    • v.30 no.6
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    • pp.507-517
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    • 1998
  • Unlike conventional fuel types, fuel constituent redistribution and sodium intrusion into the fuel slug are the unique phenomena of the irradiated metallic fuel. A thermal calculation model on metallic U-10 wt.%Zr fuel rod for LMRs is developed with considerations given to these phenomena. The amount of constituent redistribution is estimated based on the thermotransport process. The temperature profile of fuel slug is predicted by taking into account of Zr redistribution, porosity formation and sodium logging effects. A sample calculation is performed and compared to experimental data in literature. As a result, the predicted redistribution and temperature profile are well agreed with experimental data, assuming that 15 times increment of ex-reactor diffusivity, $Q_{r}$ $^{*}$ is -50 kJ/mole and sodium is infiltrated only outside of the fuel slug. Furthermore, the redistribution effects on fuel integrity and fuel temperature profile are discussed.d.

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Factors governing redistribution of moment in continuous prestressed concrete beams

  • Kodur, V.K.R.;Campbell, T.I.
    • Structural Engineering and Mechanics
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    • v.8 no.2
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    • pp.119-136
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    • 1999
  • The failure load of a continuous prestressed concrete beam depends partially on the amount of redistribution of moment that occurs prior to failure. Results from a parametric study, carried out using a nonlinear finite element computer program, are presented to demonstrate the influences of various factors on redistribution of moment in two-span, continuous bonded prestressed concrete beams. Trends in the data from the numerical studies are compared with those from a theoretical expression for percentage of redistribution, and it is shown that the redistribution of moment occurring in a continuous prestressed concrete beam is a function of number of parameters.

Design for moment redistribution in FRP plated RC beams

  • Oehlers, Deric John;Hasketta, Matthew;Mohamed Ali, M.S.
    • Structural Engineering and Mechanics
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    • v.38 no.6
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    • pp.697-714
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    • 2011
  • Assessing the ductility of reinforced concrete sections and members has been a complex and intractable problem for many years. Given the complexity in estimating ductility, members are often designed specifically for strength whilst ductility is provided implicitly through the use of ductile steel reinforcing bars and by ensuring that concrete crushing provides the ultimate limit state. As such, the empirical hinge length and neutral axis depth approaches have been sufficient to estimate ductility and moment redistribution within the bounds of the test regimes from which they were derived. However, being empirical, these methods do not have a sound structural mechanics background and consequently have severe limitations when brittle materials are used and when concrete crushing may not occur. Structural mechanics based approaches to estimating rotational capacities and rotation requirements for given amounts of moment redistribution have shown that FRP plated reinforced concrete (RC) sections can have significant moment redistribution capacities. In this paper, the concept of moment redistribution in beams is explained and it is shown specifically how an existing RC member can be retrofitted with FRP plates for both strength and ductility requirements. Furthermore, it is also shown how ductility through moment redistribution can be used to maximise the increase in strength of a member. The concept of primary and secondary hinges is also introduced and it is shown how the response of the non-hinge region influences the redistribution capacity of the primary hinges, and that for maximum moment redistribution to occur the non-hinge region needs to remain elastic.

Defect of $^{18}F-FDG$ Uptake Observed in Infarcted Myocardium Showing Reverse Redistribution on Rest / 24-Hour Delayed $^{201}Tl$ Myocardial SPEG after Acute Myocardial Infarction (급성 심근경색 후 휴식 / 24시간 지연 $^{201}Tl$ 심근 SPECT 상 역재분포를 보인 경색심근에서 관찰된 $^{18}F-FDG$ 섭취 결손)

  • Lee, Ho-Young;Paeng, Jin-Chul;Oh, So-Won;Kim, Ji-Yeong;Chung, Woo-Young
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.6
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    • pp.478-481
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    • 2008
  • Reverse redistribution is frequently observed after revascularization in acute myocardial infarction, and usually regarded as a predictor of viable myocardium on stress/rest and 2- to 4-hour redistribution $^{201}Tl$ SPECT. However, there is not enough report of reverse redistribution in case of 24-hour delayed SPECT, which is commonly used for viability assessment. In this report, a case of reverse redistribution on rest and 24-hour delayed $^{201}Tl$ SPECT is reported with use of automatic segmental quantitative analysis. The myocardium of reverse redistribution was dysfunctional on gated SPECT, and diagnosed as non-viable on $^{18}F-FDG$ PET.