Ziqiao Zhou¹, Tianyang Zhou^1,*, Jinghao Xu², Junhu Zhu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2613-2634, 2024, DOI:10.32604/cmes.2023.028553

Abstract Intelligent penetration testing is of great significance for the improvement of the security of information systems, and the critical issue is the planning of penetration test paths. In view of the difficulty for attackers to obtain complete network information in realistic network scenarios, Reinforcement Learning (RL) is a promising solution to discover the optimal penetration path under incomplete information about the target network. Existing RL-based methods are challenged by the sizeable discrete action space, which leads to difficulties in the convergence. Moreover, most methods still rely on experts’ knowledge. To address these issues, this paper… More >

Yaxun Liu^1,2, Lisheng Liu^1,2,*, Hai Mei^1,2, Qiwen Liu^1,2, Xin Lai^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09007

Abstract As a mathematical expression of the dynamic mechanical behavior, the constitutive model plays an indispensable role in numerical simulations of ceramic materials. The current bond-based peridynamic constitutive models can accurately describe the dynamic mechanical behavior of partial ceramic materials under impact loading, however, the predicted value of the Poisson’s ratio is 0.25, which is not true for most of the known ceramic materials. Herein, based on the existing bond-based peridynamic constitutive model, the current study utilizes the description of tangential bond force and considers the influence of bond force on rotation to accurately predict the… More >

Lei Zhu^1,2, Bin Liu², Xuewei Liu^2,*, Wei Deng¹, Wenjie Yao¹, Ying Fan¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 401-427, 2024, DOI:10.32604/fdmp.2023.041444

Abstract To analyze the effects of a time-varying viscosity on the penetration length of grouting, in this study cement slurries with varying water-cement ratios have been investigated using the Bingham’s fluid flow equation and a discrete element method. A fluid-solid coupling numerical model has been introduced accordingly, and its accuracy has been validated through comparison of theoretical and numerical solutions. For different fracture forms (a single fracture, a branch fracture, and a fracture network), the influence of the time-varying viscosity on the slurry length range has been investigated, considering the change in the fracture aperture. The More >

Haoran Zhang¹, Lisheng Liu^2,*, Qiwen Liu², Xin Lai²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09493

Abstract Ceramic metal composite structure with high hardness, high bending strength of ceramic materials as the front layer and materials with high tensile strength, high elongation as the backing layer, has excellent penetration resistance. The current numerical methods for studying the penetration resistance of ceramic/metal composite structures under ballistic impact still have many deficiencies. Peridynamics (PD) is a novel nonlocal theory that is well suited for simulations involving damage and fracture behavior. At present, the existing rate-dependent bond-based PD (BB-PD) constitutive model considering the rotation effect and the Johnson-Cook (JC) metal model based on non-ordinary state-based… More >

Guobin He^*, Rui Su, Jinxin Yang, Yuanping Huang, Huanlin Chen, Donghui Zhang, Cangtao Yang, Wenwen Li

Energy Engineering, Vol.120, No.9, pp. 2133-2154, 2023, DOI:10.32604/ee.2023.029007

Abstract In the framework of vigorous promotion of low-carbon power system growth as well as economic globalization, multi-resource penetration in active distribution networks has been advancing fiercely. In particular, distributed generation (DG) based on renewable energy is critical for active distribution network operation enhancement. To comprehensively analyze the accessing impact of DG in distribution networks from various parts, this paper establishes an optimal DG location and sizing planning model based on active power losses, voltage profile, pollution emissions, and the economics of DG costs as well as meteorological conditions. Subsequently, multi-objective particle swarm optimization (MOPSO) is… More >

Vijayakumar Thulasi, R. Thundil Karuppa Raj^*

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-9, 2018, DOI:10.5098/hmt.10.33

Abstract Diethyl ether is one of the potential alternative fuels for the high speed compression ignition engines that can replace the existing neat diesel fuel. It is well known that the combustion characteristic of a compression ignition engine is highly influenced by the fuel spray structure formed during the injection process. In this paper the spray structure formation for the diethyl ether fuel is studied numerically, using the discrete phase model and it is compared with the neat diesel fuel. The spray is investigated in a constant volume chamber maintained at 30 bar pressure. The fuel… More >

Akinyemi Ayodeji Stephen^*, Kabeya Musasa, Innocent Ewean Davidson

Energy Engineering, Vol.119, No.6, pp. 2711-2744, 2022, DOI:10.32604/ee.2022.023069

Abstract The occurrence of distortion and over voltage at the Point of Common Coupling (PCC) of Renewable Distributed Generation (RDG) limits its penetration levels to the power system and the RDG integration is expected to play a crucial role in power system transformation. For its penetrations to be sustained without disconnection from the system, there must be a solution to the voltage rise, distortion, unbalanced current and grid reactive power control strategy at PCC. It is an IEEE-1547 requirement that RDG integration to the power system should be regulated at PCC to avoid disconnection from the… More > Graphic Abstract

Hongliang Wang¹, Jiahua Hu¹, Danhuang Dong¹, Cenfeng Wang¹, Feixia Tang², Yizheng Wang¹, Changsen Feng^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1137-1158, 2023, DOI:10.32604/cmes.2022.021965

Abstract With the rapid and wide deployment of renewable energy, the operations of the power system are facing greater challenges when dispatching flexible resources to keep power balance. The output power of renewable energy is uncertain, and thus flexible regulation for the power balance is highly demanded. Considering the multi-timescale output characteristics of renewable energy, a flexibility evaluation method based on multi-scale morphological decomposition and a multi-timescale energy storage deployment model based on bi-level decision-making are proposed in this paper. Through the multi-timescale decomposition algorithm on the basis of mathematical morphology, the multi-timescale components are separated More >

Woo Hyun Park¹, Isma Farah Siddiqui³, Nawab Muhammad Faseeh Qureshi^2,*

CMC-Computers, Materials & Continua, Vol.73, No.3, pp. 5609-5624, 2022, DOI:10.32604/cmc.2022.030235

Abstract With the advent of the big data era, security issues in the context of artificial intelligence (AI) and data analysis are attracting research attention. In the metaverse, which will become a virtual asset in the future, users’ communication, movement with characters, text elements, etc., are required to integrate the real and virtual. However, they can be exposed to threats. Particularly, various hacker threats exist. For example, users’ assets are exposed through notices and mail alerts regularly sent to users by operators. In the future, hacker threats will increase mainly due to naturally anonymous texts. Therefore,… More >

Jiusong Chen^1,*, Dejun Miao¹, Yizong Dai¹, Mojtaba Ghadamyari^2,*

Energy Engineering, Vol.119, No.5, pp. 1985-2003, 2022, DOI:10.32604/ee.2022.021142

Abstract Electric vehicles (EVs) have received special consideration from modern society over the past several years. Although EVs are a fine example of environmentally friendly technology and have many advantages, they relatively increase the electricity demand upon a power grid as well. Therefore, their negative impact on busvoltage and line losses should be analyzed. In this study, the effect of EV loads and their penetration on bus voltage and line losses of an IEEE-33 bussystem has been examined via two scenarios. It is important to mention that the effect of EVs on the rate of air More >