Hongly Va¹, Min-Hyung Choi², Min Hong^3,*

CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 831-848, 2022, DOI:10.32604/cmc.2022.029576

Abstract This paper presents a parallel method for simulating real-time 3D deformable objects using the volume preservation mass-spring system method on tetrahedron meshes. In general, the conventional mass-spring system is manipulated as a force-driven method because it is fast, simple to implement, and the parameters can be controlled. However, the springs in traditional mass-spring system can be excessively elongated which cause severe stability and robustness issues that lead to shape restoring, simulation blow-up, and huge volume loss of the deformable object. In addition, traditional method that uses a serial process of the central processing unit (CPU) to solve the system in… More >

Yongxin Li¹, Guoyun Zhou¹, Tao Chang^1,*, Liming Yang², Fenghe Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 499-511, 2022, DOI:10.32604/cmes.2022.017630

Abstract Because of descriptive nonlinearity and computational inefficiency, topology optimization with fatigue life under aperiodic loads has developed slowly. A fatigue constraint topology optimization method based on bidirectional evolutionary structural optimization (BESO) under an aperiodic load is proposed in this paper. In view of the severe nonlinearity of fatigue damage with respect to design variables, effective stress cycles are extracted through transient dynamic analysis. Based on the Miner cumulative damage theory and life requirements, a fatigue constraint is first quantified and then transformed into a stress problem. Then, a normalized termination criterion is proposed by approximate maximum stress measured by global… More >

Jiazheng Du^*, Ying Zhang, Fanwei Meng

CMES-Computer Modeling in Engineering & Sciences, Vol.129, No.2, pp. 661-687, 2021, DOI:10.32604/cmes.2021.017580

Abstract Traditional topology optimization methods may lead to a great reduction in the redundancy of the optimized structure due to unexpected material removal at the critical components. The local failure in critical components can instantly cause the overall failure in the structure. More and more scholars have taken the fail-safe design into consideration when conducting topology optimization. A lot of good designs have been obtained in their research, though limited regarding minimizing structural compliance (maximizing stiffness) with given amount of material. In terms of practical engineering applications considering fail-safe design, it is more meaningful to seek for the lightweight structure with… More >

Jeongcheol Lee, Sunil Ahn^*, Hyunseob Kim, Jongsuk Ruth Lee

Intelligent Automation & Soft Computing, Vol.31, No.1, pp. 255-277, 2022, DOI:10.32604/iasc.2022.018558

Abstract Automated hyperparameter optimization (HPO) is a crucial and time-consuming part in the automatic generation of efficient machine learning models. Previous studies could be classified into two major categories in terms of reducing training overhead: (1) sampling a promising hyperparameter configuration and (2) pruning non-promising configurations. These adaptive sampling and resource scheduling are combined to reduce cost, increasing the number of evaluations done on more promising configurations to find the best model in a given time. That is, these strategies are preferred to identify the best-performing models at an early stage within a certain deadline. Although these time and resource constraints… More >

Lianxiong Chen¹, Hui Liu^1,*, Xihua Chu^1,2, Jiao Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.3, pp. 1197-1218, 2021, DOI:10.32604/cmes.2021.016894

Abstract Functional graded cellular structure (FGCS) usually shows superior mechanical behavior with low density and high stiffness. With the development of additive manufacturing, functional graded cellular structure gains its popularity in industries. In this paper, a novel approach for designing functionally graded cellular structure is proposed based on a subdomain parameterized level set method (PLSM) under local volume constraints (LVC). In this method, a subdomain level set function is defined, parameterized and updated on each subdomain independently making the proposed approach much faster and more cost-effective. Additionally, the microstructures on arbitrary two adjacent subdomains can be connected perfectly without any additional… More >

Jiaxiang Luo^1,2, Yu Li², Weien Zhou², Zhiqiang Gong², Zeyu Zhang¹, Wen Yao^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.3, pp. 823-848, 2021, DOI:10.32604/cmes.2021.016737

Abstract Deep learning for topology optimization has been extensively studied to reduce the cost of calculation in recent years. However, the loss function of the above method is mainly based on pixel-wise errors from the image perspective, which cannot embed the physical knowledge of topology optimization. Therefore, this paper presents an improved deep learning model to alleviate the above difficulty effectively. The feature pyramid network (FPN), a kind of deep learning model, is trained to learn the inherent physical law of topology optimization itself, of which the loss function is composed of pixel-wise errors and physical constraints. Since the calculation of… More >

Mohammed Baljon, Shailendra Mishra^*

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 129-144, 2021, DOI:10.32604/cmc.2021.017509

Abstract Energy harvesting (EH) technology in wireless communication is a promising approach to extend the lifetime of future wireless networks. A cross-layer optimal adaptation policy for a point-to-point energy harvesting (EH) wireless communication system with finite buffer constraints over a Rayleigh fading channel based on a Semi-Markov Decision Process (SMDP) is investigated. Most adaptation strategies in the literature are based on channel-dependent adaptation. However, besides considering the channel, the state of the energy capacitor and the data buffer are also involved when proposing a dynamic modulation policy for EH wireless networks. Unlike the channel-dependent policy, which is a physical layer-based optimization,… More >

Yuhang Huo¹, Ye Tian¹, Shiming Pu¹, Tielin Shi¹, Qi Xia^1,2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1087-1099, 2021, DOI:10.32604/cmes.2021.015694

Abstract In the present study, we propose to integrate the bilateral filter into the Shepard-interpolation-based method for the optimization of composite structures. The bilateral filter is used to avoid defects in the structure that may arise due to the gap/overlap of adjacent fiber tows or excessive curvature of fiber tows. According to the bilateral filter, sensitivities at design points in the filter area are smoothed by both domain filtering and range filtering. Then, the filtered sensitivities are used to update the design variables. Through several numerical examples, the effectiveness of the method was verified. More >

Tauqeer ul Amin^1,*, Basit Shahzad¹, Fazal-e-Amin², Muhammad Shoaib²

CMC-Computers, Materials & Continua, Vol.67, No.2, pp. 2665-2680, 2021, DOI:10.32604/cmc.2021.013263

Abstract Requirements elicitation is a fundamental phase of software development in which an analyst discovers the needs of different stakeholders and transforms them into requirements. This phase is cost- and time-intensive, and a project may fail if there are excessive costs and schedule overruns. COVID-19 has affected the software industry by reducing interactions between developers and customers. Such a lack of interaction is a key reason for the failure of software projects. Projects can also fail when customers do not know precisely what they want. Furthermore, selecting the unsuitable elicitation technique can also cause project failure. The present study, therefore, aimed… More >

Asadullah Shaikh^1,*, Abdul Hafeez², M. A. Elmagzoub¹, Abdullah Alghamdi¹, Ansar Siddique³, Basit Shahzad⁴

Intelligent Automation & Soft Computing, Vol.27, No.2, pp. 565-579, 2021, DOI:10.32604/iasc.2021.015071

Abstract Unified Modeling Language (UML) models are considered important artifacts of model-driven engineering (MDE). This can automatically transform models to other paradigms and programming languages. If a model has bugs, then MDE can transfer these to a new code. The class model is a key component of UML that is used in analysis and design. Without a formal foundation, UML can create only graphical diagrams, making it impossible to verify properties such as satisfiability, consistency and consequences. Different techniques have been used to verify UML class models, but these do not support some important components. This paper transforms and verifies unsupported… More >