Jie Luo^*, Qingbing Ji, Lvlin Ni

Journal on Artificial Intelligence, Vol.4, No.3, pp. 133-142, 2022, DOI:10.32604/jai.2022.031800 - 01 December 2022

Abstract How to quickly and accurately identify applications in VPN encrypted tunnels is a difficult technique. Traditional technologies such as DPI can no longer identify applications in VPN encrypted tunnel. Various VPN protocols make the feature engineering of machine learning extremely difficult. Deep learning has the advantages that feature extraction does not rely on manual labor and has a good early application in classification. This article uses deep learning technology to classify the applications of VPN encryption tunnel based on the SAE-2dCNN model. SAE can effectively reduce the dimensionality of the data, which not only improves More >

Yuxia Han^1,2, Jianwen Wang^1,2,*, Xin Li³, Xueqing Dong^1,2, Caifeng Wen^1,2

Energy Engineering, Vol.119, No.6, pp. 2297-2317, 2022, DOI:10.32604/ee.2022.020858 - 14 September 2022

Abstract The evolution laws of the large-eddy coherent structure of the wind turbine wake have been evaluated via wind tunnel experiments under uniform and turbulent inflow conditions. The spatial correlation coefficients, the turbulence integral scales and power spectrum are obtained at different tip speed ratios (TSRs) based on the time-resolved particle image velocity (TR-PIV) technique. The results indicate that the large-eddy coherent structures are more likely to dissipate with an increase in turbulence intensity and TSR. Furthermore, the spatial correlation of the longitudinal pulsation velocity is greater than its axial counterpart, resulting into a wake turbulence… More >

Binbin Lv, Jun Zha, Kaichun Zeng^*, Hongtao Guo, Li Yu and Peng Zhang

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.1, pp. 1-29, 2022, DOI:10.32604/cmes.2022.020572 - 18 July 2022

Abstract The high-performance morphing aircraft has become a research focus all over the world. The morphing aircraft, unlike regular unmanned aerial vehicles (UAVs), has more complicated aerodynamic characteristics, making itmore difficultto conduct its design, model analysis, and experimentation. This paper reviews the recent process and the current status of aeroelastic issues, numerical simulations, and wind tunnel test of morphing aircrafts. The evaluation of aerodynamic characteristics, mechanism, and relevant unsteady dynamic aerodynamic modeling throughout the morphing process are the primary technological bottlenecks formorphing aircrafts. The unstable aerodynamic forces have a significant impact on the aircraft handling characteristics,… More >

Xiaozhong Li^*, Caiyun Sun

Structural Durability & Health Monitoring, Vol.16, No.3, pp. 235-254, 2022, DOI:10.32604/sdhm.2022.013141 - 18 July 2022

Abstract During the construction of subway tunnels, safety issues should not be ignored, so it is necessary to prevent and resolve the risk in time and accurately. However, there are some shortcomings in the research of risk assessment, such as the subjectivity of initial data or the lack of scientific evaluation model, in order to solve the problem, this paper relies on the Changping section of the Guanhui Intercity Metro, in order to establish a dynamic risk-warning model for the construction process of subway tunnel with the CD-Bench composite method. First, a monitoring plan was equationted… More >

Shengjun Deng^1,2,3, Haolin Chen¹, Xiaonan Gong², Jiajin Zhou², Xiangdong Hu⁴, Gang Jiang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.1, pp. 251-266, 2022, DOI:10.32604/cmes.2022.020388 - 02 June 2022

Abstract Freeze-sealing pipe roof method is applied in the Gongbei tunnel, which causes the ground surface uplift induced by frost heave. A frost heaving prediction approach based on the coefficient of cold expansion is proposed to simulate the ground deformation of the Gongbei tunnel. The coefficient of cold expansion in the model and the frost heaving rate from the frost heave test under the hydration condition can achieve a good correspondence making the calculation result closer to the actual engineering. The ground surface uplift along the lateral and longitudinal direction are respectively analyzed and compared with… More >

Hongyun Jiao¹, Mi Zhao¹, Jingqi Huang^2,*, Xu Zhao^1,3, Xiuli Du¹

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.3, pp. 1289-1314, 2022, DOI:10.32604/cmes.2022.018540 - 19 April 2022

Abstract Tunnel portal sections often suffer serious damage in strong earthquake events. Earthquake waves may propagate in different directions, producing various dynamic responses in the tunnel portal. Based on the Galongla tunnel, which is located in a seismic region of China, three-dimensional seismic analysis is conducted to investigate the dynamic response of a tunnel portal subjected to earthquake waves with different vibration directions. In order to simulate the mechanic behavior of slope rock effectively, an elastoplastic damage model is adopted and applied to ABAQUS software by a self-compiled user material (UMAT) subroutine. Moreover, the seismic wave… More >

Deng Qin¹, Tian Li^1,*, Honglin Wang², Jizhong Yang³, Yao Jiang³, Jiye Zhang¹, Haiquan Bi²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.3, pp. 1371-1386, 2022, DOI:10.32604/cmes.2022.018480 - 30 December 2021

Abstract The aerodynamic noise of high-speed trains passing through a tunnel has gradually become an important issue. Numerical approaches for predicting the aerodynamic noise sources of high-speed trains running in tunnels are the key to alleviating aerodynamic noise issues. In this paper, two typical numerical methods are used to calculate the aerodynamic noise of high-speed trains. These are the static method combined with non-reflective boundary conditions and the dynamic mesh method combined with adaptive mesh. The fluctuating pressure, flow field and aerodynamic noise source are numerically simulated using the above methods. The results show that the More >

Jianhui Yang¹, Kai Shen¹, Shoudong Pan², Shuren Wang^3,*, Zhengsheng Zou³

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 243-255, 2022, DOI:10.32604/fdmp.2022.016677 - 16 December 2021

Abstract The large deformation of soft rock tunnel is one of the key problems to be overcome in the tunnel construction stage. In the present study, the deformation mechanism of a representative tunnel and some related countermeasures are investigated using field tests and engineering geological analysis. Owing to the scarce performances of methods based on other criteria such as small pipe spacing, anchor bolt length and steel frame spacing, a new support scheme is implemented and optimized. Results show that shear failure and bedding sliding are produced under high horizontal stress conditions. The low strength of More >

Md Abdus Samad^1,2, Dong-You Choi^1,*

CMC-Computers, Materials & Continua, Vol.71, No.2, pp. 3127-3143, 2022, DOI:10.32604/cmc.2022.023086 - 07 December 2021

Abstract In present-day society, train tunnels are extensively used as a means of transportation. Therefore, to ensure safety, streamlined train operations, and uninterrupted internet access inside train tunnels, reliable wave propagation modeling is required. We have experimented and measured wave propagation models in a 1674 m long straight train tunnel in South Korea. The measured path loss and the received signal strength were modeled with the Close-In (CI), Floating intercept (FI), CI model with a frequency-weighted path loss exponent (CIF), and alpha-beta-gamma (ABG) models, where the model parameters were determined using minimum mean square error (MMSE)… More >

Tengfei Tu^1,2, Wei Yin³, Hua Zhang^1,2,*, Xingyu Zeng¹, Xiaoxiang Deng¹, Yuchen Zhou¹, Xu Liu⁴

CMC-Computers, Materials & Continua, Vol.71, No.2, pp. 2315-2331, 2022, DOI:10.32604/cmc.2022.022540 - 07 December 2021

Abstract The Internet Control Message Protocol (ICMP) covert tunnel refers to a network attack that encapsulates malicious data in the data part of the ICMP protocol for transmission. Its concealment is stronger and it is not easy to be discovered. Most detection methods are detecting the existence of channels instead of clarifying specific attack intentions. In this paper, we propose an ICMP covert tunnel attack intent detection framework ICMPTend, which includes five steps: data collection, feature dictionary construction, data preprocessing, model construction, and attack intent prediction. ICMPTend can detect a variety of attack intentions, such as… More >