Omar H. Abdalla^1,*, Gamal Abdel-Salam², Azza A. A. Mostafa³

Energy Engineering, Vol.119, No.2, pp. 569-589, 2022, DOI:10.32604/ee.2022.018693

Abstract Battery Energy Storage System (BESS) is one of the potential solutions to increase energy system flexibility, as BESS is well suited to solve many challenges in transmission and distribution networks. Examples of distribution network’s challenges, which affect network performance, are: (i) Load disconnection or technical constraints violation, which may happen during reconfiguration after fault, (ii) Unpredictable power generation change due to Photovoltaic (PV) penetration, (iii) Undesirable PV reverse power, and (iv) Low Load Factor (LF) which may affect electricity price. In this paper, the BESS is used to support distribution networks in reconfiguration after a fault, increasing Photovoltaic (PV) penetration,… More >

Zhihao Zheng¹, Yanbo Che^1,*, Hailian Bi¹, Dan Wu¹, Wei He²

Energy Engineering, Vol.119, No.2, pp. 637-651, 2022, DOI:10.32604/ee.2022.016661

Abstract With the implementation of electric energy alternatives, the large-scale application of electric energy substitution represented by air-source heat pumps has replaced traditional coal-fired heating, which is beneficial for the environment and alleviates air pollution. However, the large-scale application of air-source heat pumps has brought power quality problems such as voltage sags, harmonic pollution, and three-phase imbalance to the distribution network. This paper studies the fixed-frequency and variable-frequency air-source heat pump, introduces its working principle, analyzes the mechanism of its power quality problem. Moreover, the paper establishes a simulation model for the fixed-frequency heat pump and variable-frequency heat pump to connect… More >

Bandar Abdulrhman Bin Arfaj¹, Shailendra Mishra^2,*, Mohammed Alshehri¹

Intelligent Automation & Soft Computing, Vol.31, No.1, pp. 223-239, 2022, DOI:10.32604/iasc.2022.019485

Abstract The financial and confidential cost of cyberattack has presented a significant loss to the organization and government where the privacy of worthless information has become vulnerable to cyber threat. In terms of efforts implemented to avoid this risk, the cyberattack continues to evolve, making the cybersecurity systems weekend. This has necessitated the importance of comprehensive penetration testing, assessment techniques, and tools to analyze and present the currently available unconventional penetration techniques and tactics to test and examine their key features and role in supporting cybersecurity and measure their effectiveness. The importance of cyberspace and its value make it an eminent… More >

Zhiqiang Shu¹, Jianmin Wu^1,*, Shi Chen², Shan Yi², Shaoqing Li¹

Journal of Renewable Materials, Vol.10, No.2, pp. 453-467, 2022, DOI:10.32604/jrm.2022.016828

Abstract Steel slag is regarded as one of the most widespread solid by-products of steel smelting with little commercial value. It can play a vital role in the construction industry especially in the field of transportation infrastructure construction. However, there are few evaluation systems established on the high-temperature deformation and low-temperature fracture behavior of steel slag rubber asphalt mixture (SSRAM). This study explores the performance of SSRAM by uniaxial penetration test, Semi-Circular Bending (SCB) test and evaluates test data through regression analysis. The uniaxial penetration test results shows that the failure deformation of SSRAM increases with the increase of steel slag… More >

Shaomin Liang, Lu Liu, Shunying Ji^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 145-160, 2021, DOI:10.32604/cmes.2021.016403

Abstract Based on the discrete element method and hydrostatics theory, an improved Archimedes principle is proposed to study the rules pertaining to resistance changes during the penetration process of an intruder into the particulate materials. The results illustrate the fact that the lateral contribution to the resistance is very small, while the tangential force of the lateral resistance originates from friction effects. Conversely, the resistance of particulate materials on the intruder mainly occurs at the bottom part of the intruding object. Correspondingly, the factors that determine the resistance of the bottom part of the intruding object and the rules pertaining to… More >

Yehan Xu, Zhifu Dong, Chong Jia, Zhiqiang Wang^*, Xiaoning Lu^*

Journal of Renewable Materials, Vol.9, No.9, pp. 1609-1620, 2021, DOI:10.32604/jrm.2021.015193

Abstract

Nail connection is widely used in engineering and construction fields. In this study, bamboo nail was proposed as a novel connector for timber assemblies. Penetration depth of bamboo nail into wood was predicted and tested. The influence of nail parameters (length, radius and ogive radius) on penetration depth were verified. For both tested and predicted results, the penetration depth of bamboo nail increased with the increasing length, radius or ogive radius. In addition, the effect of densification on penetration depth or mechanical properties was evaluated. 1.12 g/cm³ was a critical density when densification was needed, and further increment of density… More >

Tingting Zhao¹, Y. T. Feng^2,*, Jie Zhang¹, Zhihua Wang¹, Zhiyong Wang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 721-735, 2021, DOI:10.32604/cmes.2021.015913

Abstract This paper presents a convex polyhedral based discrete element method for modelling the dynamic behaviour of rockfills for resisting high speed projectile penetration. The contact between two convex polyhedra is defined by the Minkowski overlap and determined by the GJK and EPA algorithm. The contact force is calculated by a Minkowski overlap based normal model. The rotational motion of polyhedral particles is solved by employing a quaternion based orientation representation scheme. The energy-conserving nature of the polyhedral DEM method ensures a robust and effective modelling of convex particle systems. The method is applied to simulate the dynamic behaviour of a… More >

Yichao Zang^1,*, Tairan Hu², Tianyang Zhou², Wanjiang Deng³

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 2573-2585, 2021, DOI:10.32604/cmc.2021.012220

Abstract Mining penetration testing semantic knowledge hidden in vast amounts of raw penetration testing data is of vital importance for automated penetration testing. Associative rule mining, a data mining technique, has been studied and explored for a long time. However, few studies have focused on knowledge discovery in the penetration testing area. The experimental result reveals that the long-tail distribution of penetration testing data nullifies the effectiveness of associative rule mining algorithms that are based on frequent pattern. To address this problem, a Bayesian inference based penetration semantic knowledge mining algorithm is proposed. First, a directed bipartite graph model, a kind… More >

Tanzhong Fu^1,2,3, Yu Xue^1,*, Tancai Xia¹, Wang Jing¹, De Gejirifu¹

Energy Engineering, Vol.117, No.6, pp. 397-411, 2020, DOI:10.32604/EE.2020.011633

Abstract To further study the impact of renewable energy penetration on the technical transformation of distribution networks. Based on the output power characteristics of wind power and photovoltaics, a renewable energy grid-connected capacity model and a distribution network full cost-benefit model were constructed. Based on this, to maximize the comprehensive income of the distribution network and the renewable energy penetration rate, to establish the technical reform optimization model and search for the optimal solution through the improved NSGA-II algorithm. Finally, the effectiveness of the proposed model was verified by setting up three scenarios of simultaneous wind power, grid-connected wind power, grid-connected… More >

Xiangyu Gao, Weidong Yang^*, Hongxuan Xian, Xiyuan Tu, Yuanyuang Wang^*

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 227-241, 2020, DOI:10.32604/cmes.2020.09923

Abstract This paper studies the binder droplet injection process in the 3DP technique. The mathematical model of the binder penetration process for multi-nozzle and multi-layer in 3DP technique is established, by using the conservation Level set method. According to the two-dimensional plane model of three-dimensional spatial structure of sand bed, the construction method of an equivalent cylindrical mapping infiltration model is proposed to represent the porosity of the model in the two-dimensional plane, which is exactly the same as that in the three-dimensional space, as well as closer to the arrangement of the three-dimensional space, and to realize the differentiation between… More >