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Android Malware Detection Method Based on Permission Complement and API Calls

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Chinese Journal of Electronics 2022年第4期31卷 773-785页

作者： yanG Jiyun tang Jiang yan Ran XIANG Tao College of Computer Science Chongqing University

The dynamic code loading mechanism of the Android system allows an application to load executable files externally at runtime. This mechanism makes the development of applications more convenient, but it also brings security issues. Applications that hide malicious behavior in the external file by dynamic code loading are becoming a new challenge for Android malware detection. To overcome this challenge, based on dynamic code loading mechanisms, three types of threat models,i.e. Model I, Model II, and Model III are defined. For the Model I type malware, its malicious behavior occurs in Dex Code, so the application programming interface(API)classes were used to characterize the behavior of the DexCode file. For the Model II type and Model III type malwares whose malicious behaviors occur in an external file,the permission complement is defined to characterize the behaviors of the external file. Based on permission complement and API calls, an Android malicious application detection method is proposed, of which feature sets are constructed by improving a feature selection method. Five datasets containing 15,581 samples are used to evaluate the performance of the proposed method. The experimental results show that our detection method achieves accuracy of 99.885% on general dataset, and performes the best on all evaluation metrics on all datasets in all comparison methods.

关键词： Android Malware detection Dynamic code loading Permission complement

Simulation on Evaporation and Motion of Atomized Droplets in Spray Dry Flue Gas Desulfurization Tower

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Journal of Thermal Science 2022年第6期31卷 2252-2263页

作者： ZHANG Tengfei tang Qiang PU Chao yan Yunfei Key Laboratory of Low-grade Energy Utilization Technologies and Systems Ministry of EducationChongqing UniversityChongqing400044China

The evaporation and motion of atomized droplets have an essential effect on the safe and efficient long-term operation of the desulphurization tower. Therefore, the two-phase flow model is established and solved by three-dimensional steady Reynolds-averaged Navier-Stokes equations;the droplets are tracked by Eulerian-Lagrangian method. The three factors, including inlet swirling flow of flue gas, initial droplet diameter, and inlet flue gas temperature, are analyzed to show the effects on the evaporation and motion of atomized droplets, respectively. The results show that the swirling flow of flue gas and initial droplet diameter dominate the penetration length of the atomized droplets and the mixing characteristic of droplets and flue gas. With the increase of droplet diameter, the length of droplet penetrating flue gas increases. When droplet diameter is 200 μm and inlet swirl number is 0.35, droplets completely penetrate the core area. Therefore, this is the maximum initial droplet diameter at the inlet swirl number of 0.35. The droplets evaporation time of initial 150 μm diameter is 85.5% longer than that of 50 μm droplets(0.35 of inlet swirl number). Increasing the inlet flue gas temperature can enhance the heat transfer. When inlet flue gas temperature rises from 483 K to 523 K, the evaporation time decreases by 33.8%. The results can be used to guide the optimization of droplets spray evaporation under practical operating conditions in the desulfurization tower.

关键词： spray dry FGD atomized droplets swirling flow penetration length droplet evaporation

Two-phase guidance law for impact time control under physical constraints

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Chinese Journal of Aeronautics 2020年第11期33卷 2946-2958页

作者： yang tang Xiaoping ZHU Zhou ZHOU Fei yan National Key Laboratory of Science and Technology on UAV Northwestern Polytechnical UniversityXi’an 710065China UAV Research Institute Northwestern Polytechnical UniversityXi'an 710065China School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

An impact-time-control guidance law is required for the simultaneous attack of suicide attack unmanned aerial *** on the nonlinear model,a two-phase guidance strategy is *** impact time is derived in a simple analytical form of initial states and switching states,and it can be controlled by switching at an appropriate ***,a two-phase guidance law is designed to make the magnitude of the heading error decrease monotonically from its initial value to *** then,the feasible interval of the switching ranges and of the impact times under the acceleration constraint are given analytically in ***,a general form of twophase guidance law is proposed,which allows the magnitude of the heading error to increase in the first phase,to improve the applicability of the *** the same structure as proportional navigation guidance with a time-varying gain,the proposed algorithms are simple and easy to *** corresponding feedback form is presented for realistic *** a predefined impact time is taken within its permissible set,the constraints on the acceleration and fieldof-view will not be violated during the ***,simulations validate the effectiveness of the methodology in impact time control and salvo attack.

关键词： Acceleration constraint Field-of-view constraint Guidance Impact time control Switching

Nonlinear Analysis of Bidirectional Vortex-Induced Vibration of A Deepwater Steep Wave Riser Subjected to Oblique Currents

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China Ocean Engineering 2021年第6期35卷 852-865页

作者： CHENG Yong tang Lian-yang JI Chun-yan School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Nippon Kaiji Kyokai(China)Co. LtdShanghai 200336China

An improved three-dimensional(3D)time-domain couple model is established in this paper to simulate the bidirectional vortex-induced vibration(VIV)of a deepwater steep wave riser(SWR)subjected to oblique *** this model,the nonlinear motion equations of the riser are established in the global coordinate system based on the slender rod theory with the finite element *** der Pol equations are used to describe the lift forces induced by the x-and y-direction current components,*** coupled equations at each time step are solved by a Newmark-βiterative scheme for the SWR *** present model is verified by comparison with the published experimental results for a top-tension ***,a series of simulations are executed to determine the influences of the oblique angle/velocity of the current,different top-end positions and the length of the buoyancy segment on the VIV displacement,oscillating frequency as well as hydrodynamic coefficients of the *** results demonstrate that there exists a coupled resonant VIV corresponding to x-direction and y-direction,***,the effective frequency is almost identical between the vibrations at the hang-off segment along x and y *** addition of the buoyancy modules in the middle of the SWR has a beneficial impact on the lift force of three segments and simultaneously limits the VIV response,especially at the decline segment and the hang-off ***,the incident current direction significantly affects the motion trajectory of the SWR which mainly includes the fusiform and rectangle shapes.

关键词： steep wave riser(SWR) bidirectional vortex-induced vibration wake oscillator model time-domain finite element method(TDFEM)

Time-Domain Nonlinear Wave-Current Interaction with A Steep Wave Riser Considering Internal Flow Effect

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China Ocean Engineering 2021年第3期35卷 410-421页

作者： tang Lian-yang CHENG Yong JI Chun-yan School of naval architecture and ocean engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Nippon Kaiji Kyokai(China)Co. LtdShanghai 200336China

The nonlinear dynamic response induced by the wave-current interaction on a deepwater steep wave riser(SWR)is numerically investigated based on a three-dimensional(3 D)time-domain finite element method(FEM).The governing equation considering internal flow is established in the global coordinate *** whole SWR consists of three segments:the decline segment,buoyancy segment and hang-off segment,in which the buoyancy segment is wrapped by several buoyancy modules in the middle section,leading to the arch bend and sag bend.A Newmark-β iterative scheme is adopted for the accurate analysis to solve the governing equation and update the dynamic response at each time *** proposed method is verified through the published results for the dynamic response of steel catenary riser(SCR)and static configuration of steel lazy wave riser(SLWR).Simulations are executed to study the influence of wave height,current velocity/direction,internal flow density/velocity and top-end pressure on the tension,configuration and bending moment of the *** results indicate that the influence of the current on the configuration and mechanical behavior of the SWR is greater than that of the wave,especially in the middle *** increasing current velocity,the suspending height of the middle section drops,meanwhile,its bending moment decreases accordingly,but the tension increases *** a fixed external load,the increasing internal flow density induces the amplification of the tension at the hang-off segment and the mitigation at the decline segment,while the opposite trend occurs at the bending moment.

关键词： steep wave riser(SWR) nonlinear dynamic response wave-current interaction time-domain finite element method(FEM)

Microseismic event waveform classification using CNN-based transfer learning models

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International Journal of Mining Science and Technology 2023年第10期33卷 1203-1216页

作者： Longjun Dong Hongmei Shu Zheng tang Xianhang yan School of Resources and Safety Engineering Central South UniversityChangsha 410083China International College of Digital Innovation Chiang Mai UniversityChiang Mai 50200Thailand

The efficient processing of large amounts of data collected by the microseismic monitoring system(MMS),especially the rapid identification of microseismic events in explosions and noise,is essential for mine disaster ***,this work is primarily performed by skilled technicians,which results in severe workloads and *** this paper,CNN-based transfer learning combined with computer vision technology was used to achieve automatic recognition and classification of multichannel microseismic signal ***,data collected by MMS was generated into 6-channel original waveforms based on *** that,sample data sets of microseismic events,blasts,drillings,and noises were established through manual *** datasets were split into training sets and test sets according to a certain proportion,and transfer learning was performed on AlexNet,GoogLeNet,and ResNet50 pre-training network models,*** training and tuning,optimal models were retained and compared with support vector machine *** show that transfer learning models perform well on different test ***,GoogLeNet performed best,with a recognition accuracy of 99.8%.Finally,the possible effects of the number of training sets and the imbalance of different types of sample data on the accuracy and effectiveness of classification models were discussed.

关键词： Mine safety Machine learning Transfer learning Microseismic events Waveform classification Image identification and classification

Analyzing topics in social media for improving digital twinning based product development

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Digital Communications and Networks 2024年第2期10卷 273-281页

作者： Wenyi tang Ling Tian Xu Zheng Ke yan School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

Digital twinning enables manufacturers to create digital representations of physical entities,thus implementing virtual simulations for product *** efforts of digital twinning neglect the decisive consumer feedback in product development stages,failing to cover the gap between physical and digital *** work mines real-world consumer feedbacks through social media topics,which is significant to product *** specifically analyze the prevalent time of a product topic,giving an insight into both consumer attention and the widely-discussed time of a *** primary body of current studies regards the prevalent time prediction as an accompanying task or assumes the existence of a preset ***,these proposed solutions are either biased in focused objectives and underlying patterns or weak in the capability of generalization towards diverse *** this end,this work combines deep learning and survival analysis to predict the prevalent time of *** propose a specialized deep survival model which consists of two *** first module enriches input covariates by incorporating latent features of the time-varying text,and the second module fully captures the temporal pattern of a rumor by a recurrent network ***,a specific loss function different from regular survival models is proposed to achieve a more reasonable *** experiments on real-world datasets demonstrate that our model significantly outperforms the state-of-the-art methods.

关键词： Digital twinning Product development Topic analysis Social media

Calcium/calmodulin modulates salt responses by binding a novel interacting protein SAMS1 in peanut(Arachis hypogaea L.)

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The Crop Journal 2023年第1期11卷 21-32页

作者： Sha yang Jianguo wang Zhaohui tang yan Li Jialei Zhang Feng Guo Jingjing Meng Feng Cui Xinguo Li Shubo wan Institute of Crop Germplasm Resources Shandong Academy of Agricultural SciencesJinan 250100ShandongChina Institute of Agricultural Resources and Environment Shandong Academy of Agricultural SciencesJinan 250100ShandongChina Shandong Academy of Agricultural Sciences/Shandong Provincial Key Laboratory of Crop Genetic Improvement Ecology and PhysiologyJinan 250100ShandongChina

The Ca^(2+)/CaM signal transduction pathway helps plants adapt to environmental stress. However, our knowledge on the functional proteins of C^(2+)/CaM pathway in peanut(Arachis hypogeae L.) remains limited. In the present study, a novel calmodulin 4(CaM4)-binding protein S-adenosyl-methionine synthetase 1(SAMS1) in peanut was identified using a yeast two-hybrid assay. Expression of AhSAMS1was induced by Ca^(2+), ABA, and salt stress. To elucidate the function of AhSAMS1, physiological and phenotypic analyses were performed with wild-type and transgenic materials. Overexpression of AhSAMS1increased spermidine and spermidine synthesis while decreased the contents of ethylene, thereby eliminating excessive reactive oxygen species(ROS) in transgenic lines under salt stress. AhSAMS1 reduced uptake of Na+and leakage of K+from mesophyll cells, and was less sensitive to salt stress during early seedling growth, in agreement with the induction of SOS and NHX genes Transcriptomics combined with epigenetic regulation uncovered relationships between differentially expressed genes and differentially methylated regions, which raised the salt tolerance and plants growth. Our findings support a model in which the role of AhSAMS1 in the ROS-dependent regulation of ion homeostasis was enhanced by Ca^(2+)/CaM while AhSAMS1-induced methylation was regulated by CaM, thus providing a new strategy for increasing the tolerance of plants to salt stress.

关键词： AhCaM4 AhSAMS1 Protein interaction Polyamines Salt tolerance

Three-dimensional Numerical Study on Temperature Field of Laser Bending of Sheet Metal

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Journal of Materials Science & Technology 2003年第z1期19卷 59-61页

作者： Shunhong LIU Xiong FANG Pengteng wan Jing yan Department of Materials Engineering Huazhong University of Science and Technology Wuhan 430074 China Department of Materials Engineering Huazhong University of Science and Technology Wuhan 430074 China Department of Materials Engineering Huazhong University of Science and Technology Wuhan 430074 China Department of Materials Engineering Huazhong University of Science and Technology Wuhan 430074 China

Laser bending of sheet metal is a flexible forming technique by using laser scanning. Based of temperature gradsmechanism, the temperature field of sheet metal bending process by using single laser scanning is studied with theANSYS soft. A finite element model of temperature field is built. The dynamic variation process and distributionof temperature field of laser bending at given parameters are analyzed. Furthermore, the influence parameter on thepeak temperature and temperature grads are also studied.

关键词： Laser bending, Temperature field, Numerical simulation