Danhe Chen^1,*, A. A. Baranov², Chuangge Wang¹, M. O. Karatunov³, N. Yu. Makarov³

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 977-991, 2021, DOI:10.32604/cmes.2021.014662

Abstract As the number of space objects (SO) increases, collision avoidance problem in the rendezvous tasks or re-constellation of satellites with SO has been paid more attention, and the dangerous area of a possible collision should be derived. In this paper, a maneuvering method is proposed for avoiding collision with a space debris object in the phasing orbit of the initial optimal solution. Accordingly, based on the plane of eccentricity vector components, relevant dangerous area which is bounded by two parallel lines is formulated. The axises of eccentricity vector system pass through the end of eccentricity vector of phasing orbit in… More >

Safia Akram^*, Alia Razia

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 901-922, 2021, DOI:10.32604/cmes.2021.014469

Abstract This article brings into focus the hybrid effects of thermal and concentration convection on peristaltic pumping of fourth grade nanofluids in an inclined tapered channel. First, the brief mathematical modelling of the fourth grade nanofluids is provided along with thermal and concentration convection. The Lubrication method is used to simplify the partial differential equations which are tremendously nonlinear. Further, analytical technique is applied to solve the differential equations that are strongly nonlinear in nature, and exact solutions of temperature, volume fraction of nanoparticles, and concentration are studied. Numerical and graphical findings manifest the influence of various physical flow-quantity parameters. It… More >

Annan Jiang^*, Xinping Guo, Shuai Zheng, Mengfei Xu

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 1177-1199, 2021, DOI:10.32604/cmes.2021.014199

Abstract Due to the geological body uncertainty, the identification of the surrounding rock parameters in the tunnel construction process is of great significance to the calculation of tunnel stability. The ubiquitous-joint model and three-dimensional numerical simulation have advantages in the parameter identification of surrounding rock with weak planes, but conventional methods have certain problems, such as a large number of parameters and large time consumption. To solve the problems, this study combines the orthogonal design, Gaussian process (GP) regression, and difference evolution (DE) optimization, and it constructs the parameters identification method of the jointed surrounding rock. The calculation process of parameters… More >

Chao-Feng Shih¹, Yung-Wei Chen^1,3,*, Jiang-Ren Chang², Shih-Ping Soon¹

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.3, pp. 993-1012, 2021, DOI:10.32604/cmes.2021.012702

Abstract

In this paper, the equal-norm multiple-scale Trefftz method combined with the implicit Lie-group scheme is applied to solve the two-dimensional nonlinear sloshing problem with baffles. When considering solving sloshing problems with baffles by using boundary integral methods, degenerate geometry and problems of numerical instability are inevitable. To avoid numerical instability, the multiple-scale characteristic lengths are introduced into T-complete basis functions to efficiently govern the high-order oscillation disturbance. Again, the numerical noise propagation at each time step is eliminated by the vector regularization method and the group-preserving scheme. A weighting factor of the group-preserving scheme is introduced into a linear system… More >

Yang Wang¹, Hanxi Wang^2,*, Linwei Yang¹, Li Qian¹

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.4, pp. 845-857, 2021, DOI:10.32604/fdmp.2021.015961

Abstract In order to analyze the coupled influence of temperature and humidity on early-age concrete (including cement and copper tailings), a mathematical model is introduced on the basis of the Krstulovic-Dabic hydration reaction kinetic equations. In such a framework, the influence of hydration-released heat and water consumption are also taken into account. The results provided by such a model are verified by means of experiments and related sensor measurements. The research results show that this model can adequately predict the internal temperature and the humidity temporal evolution laws. More >

Qinghai Li¹, Ziyi Zhao², Hao Wu^1,*, Xiaoyu Li^3,*, Qinsheng Zhu¹, Shan Yang⁴

Journal of Quantum Computing, Vol.3, No.1, pp. 35-43, 2021, DOI:10.32604/jqc.2021.016634

Abstract In the detection process of classic radars such as radar/lidar, the detection performance will be weakened due to the presence of background noise and loss. The quantum illumination protocol can use the spatial correlation between photon pairs to improve image quality and enhance radar detection performance, even in the presence of loss and noise. Based on this quantum illumination LIDAR, a theoretic scheme is developed for the detection and tracking of moving targets, and the trajectory of the object is analyzed. Illuminated by the quantum light source as Spontaneous Parametric Down-Conversion (SPDC), an opaque target can be identified from the… More >

Wenxiao Wang^1,*, Xiaoyu Li^1,*, Yin Ding¹, Feizhou Wu², Shan Yang³

Journal of Quantum Computing, Vol.3, No.1, pp. 25-33, 2021, DOI:10.32604/jqc.2021.016346

Abstract Due to the increase in the types of business and equipment in telecommunications companies, the performance index data collected in the operation and maintenance process varies greatly. The diversity of index data makes it very difficult to perform high-precision capacity prediction. In order to improve the forecasting efficiency of related indexes, this paper designs a classification method of capacity index data, which divides the capacity index data into trend type, periodic type and irregular type. Then for the prediction of trend data, it proposes a capacity index prediction model based on Recurrent Neural Network (RNN), denoted as RNN-LSTM-LSTM. This model… More >

Peng Wei, Mingdao Lu, Xuehan Zhang, Yilei Teng^*

Journal of Quantum Computing, Vol.3, No.1, pp. 13-23, 2021, DOI:10.32604/jqc.2021.016324

Abstract Aviation service plays an indispensable role in the process of social and economic development. In this process, the problem of flight punctuality becomes more and more serious. Flight delay will bring a variety of implicit and explicit losses to individual passengers and airlines, so it is necessary to analyze the influencing factors of flight punctuality rate. Complex network can be used to study various objects with complex relations, obtain the relations of these objects and calculate the influence of different indicators on the objects. This article mainly has carried on the three aspects: Firstly, get the flight data from the… More >

Mingdao Lu, Peng Wei, Mingshu He^*, Yinglei Teng

Journal of Quantum Computing, Vol.3, No.1, pp. 1-12, 2021, DOI:10.32604/jqc.2021.016315

Abstract With the increasing of civil aviation business, flight delay has become a key problem in civil aviation field in recent years, which has brought a considerable economic impact to airlines and related industries. The delay prediction of specific flights is very important for airlines’ plan, airport resource allocation, insurance company strategy and personal arrangement. The influence factors of flight delay have high complexity and non-linear relationship. The different situations of various regions and airports, and even the deviation of airport or airline arrangement all have certain influence on flight delay, which makes the prediction more difficult. In view of the… More >

Shuan Liu¹, Sitong Chen², Xiaohong Zhu³, Brendon Stubbs⁴, Qian Yu⁵, Mark D. Griffiths⁶, Can Jiao⁷, Aiguo Chen⁸, Md Mahbub Hossain⁹, Zsolt Demetrovics^10,11, Albert S. Yeung¹², Jinming Li⁵, Xingyu Zhang⁵, Liye Zou^5,*

International Journal of Mental Health Promotion, Vol.23, No.2, pp. 141-153, 2021, DOI:10.32604/IJMHP.2021.016274

Abstract Little is known about the role of active school travel (AST) on mental health among adolescents. Thus, this study aimed to explore the AST-depression association among adolescents aged 12–15 years from 26 low- and middleincome countries (LMICs). Data from the Global School-based Student Health Survey were analyzed in 51,702 adolescents [mean (SD) age 13.8 (1.0) years; 49.3% boys). Both depressive symptoms and AST were assessed by a single question self-reported measure, respectively. Participants who reported having 5 days or above were considered as AST. Multivariable logistic regression analysis (accounting for sampling weights) was performed while controlling for gender, age, physical… More >