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Rassan, Iehab AL;Alarif, Noof
- International Journal of Computer Science & Network Security
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- v.21 no.2
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- pp.158-170
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- 2021
Virtualization technologies are being adopted and broadly utilized in many fields and at different levels. In cloud computing, achieving load balancing across large distributed virtual machines is considered a complex optimization problem with an essential importance in cloud computing systems and data centers as the overloading or underloading of tasks on VMs may cause multiple issues in the cloud system like longer execution time, machine failure, high power consumption, etc. Therefore, load balancing mechanism is an important aspect in cloud computing that assist in overcoming different performance issues. In this research, we propose a new approach that combines the advantages of different task allocation algorithms like Round robin algorithm, and Random allocation with different threshold techniques like the VM utilization and the number of allocation counts using least connection mechanism. We performed extensive simulations and experiments that augment different scheduling policies to overcome the resource utilization problem without compromising other performance measures like makespan and execution time of the tasks. The proposed system provided better results compared to the original round robin as it takes into consideration the dynamic state of the system.
https://doi.org/10.22937/IJCSNS.2021.21.2.18 인용 PDF KSCI

Kim, Jun-Young;Lee, Jong Min;Park, Jun Geun;Kim, Jong-Sung;Cho, Min Ki;Ahn, Sang Won;Koo, Gyeong-Hoi;Lee, Bong Hee;Huh, Nam-Su;Kim, Yun-Jae;Kim, Jong-In;Nam, Il-Kwun
- Nuclear Engineering and Technology
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- v.54 no.1
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- pp.343-356
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- 2022
As a part of round robin analysis to develop a finite element elastic-plastic seismic analysis procedure for nuclear safety class 1 components, a series of parametric analyses was carried out on the simulated pressurizer surge line system model to investigate sensitivity of the analysis results to finite element analysis variables. The analysis on the surge line system model considered dynamic effect due to the seismic load corresponding to PGA 0.6 g and elastic-plastic material behavior based on the Chaboche combined hardening model. From the parametric analysis results, it was found that strains such as accumulated equivalent plastic strain and equivalent plastic strain are more sensitive to the analysis variables than von Mises effect stress. The parametric analysis results also identified that finite element density and ovalization option in the elbow elements have more significant effect on the analysis results than the other variables.
https://doi.org/10.1016/j.net.2021.07.009 인용 PDF KSCI

Sung-Kyun Jung;Jun-Young Jeon;Chan-kyu Kim;Chang-Sik Oh;Sung-Sik Kang;Chang-Young Oh
- Transactions of the Korean Society of Pressure Vessels and Piping
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- v.19 no.2
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- pp.130-139
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- 2023
This paper examines the quantification of uncertainty for welding residual stresses in dissimilar metal welds used in nuclear power plants. A mock-up of a dissimilar metal weld pipe, consisting of carbon and stainless steel pipes, was fabricated to measure the residual stress. A Round-Robin analysis was conducted by Korean institutions to assess the welding residual stress. The analysis was carried out in the second order, and the data obtained by each institution was evaluated based on the information provided. Using the Round-Robin results, the distribution of uncertainty in welding residual stresses among Korean institutions was evaluated. The quantification of uncertainty for Korean institutions was found to have a wider range compared to the distribution of welding residual stresses observed in overseas institutions. This study is considered useful in the establishment of comprehensive strategies for evaluating welding residual stress analysis methods used by domestic institutions.
https://doi.org/10.20466/KPVP.202.19.2.130 인용 PDF