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Detection of Turbulence Anomalies Using a Symbolic Classifier Algorithm in Airborne Quick Access Record(QAR)Data Analysis

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Advances in Atmospheric Sciences 2024年第7期41卷 1438-1449页

作者： Zibo ZHUANG Kunyun LIN Hongying ZHANG Pak-Wai CHAN Flight Academy Civil Aviation University of ChinaTianjin 300300China School of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China aviation Weather Services Hong Kong ObservatoryHong KongChina

As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation *** eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil *** study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)*** detection of atmospheric turbulence is approached as an anomaly detection *** evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence ***,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently *** summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning *** finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards.

关键词： turbulence detection symbolic classifier quick access recorder data

BDSec:Security Authentication Protocol for BeiDou-Ⅱ civil Navigation Message

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China Communications 2024年第6期21卷 206-218页

作者： Wu Zhijun Zhang Yuan Yang Yiming Wang Peng Yue Meng School of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China School of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China

Due to the lack of authentication mechanism in BeiDou navigation satellite system(BDS),BD-Ⅱ civil navigation message(BDⅡ-CNAV) are vulnerable to spoofing attack and replay *** solve this problem,we present a security authentication protocol,called as BDSec,which is designed by using China’s cryptography Shangyong Mima(SM) series algorithms,such as SM2/4/9 and Zu Chongzhi(ZUC)*** BDSec protocol,both of BDⅡ-CNAV and signature information are encrypted using the SM4 algorithm(Symmetric encryption mechanism).The encrypted result is used as the subject authentication *** protocol applies SM9 algorithm(Identity-based cryptography mechanism) to protect the integrity of the BDⅡ-CNAV,adopts the SM2 algorithm(Public key cryptosystem) to guarantee the confidentiality of the important session information,and uses the ZUC algorithm(Encryption and integrity algorithm) to verify the integrity of the message authentication serial number and initial information and the information in authentication initialization sub-protocol *** results of the SVO logic reasoning and performance analysis show that BDSec protocol meets security requirements for the dual user identity authentication in BDS and can realize the security authentication of BDⅡ-CNAV.

关键词： BDII civil navigation messages(BDIICNAV) BeiDou navigation satellite system(BDS) identity-based cryptography mechanism navigation message authentication protocol(BDSec)

An Innovative Deep Architecture for Flight Safety Risk Assessment Based on Time Series Data

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2549-2569页

作者： Hong Sun Fangquan Yang Peiwen Zhang Yang Jiao Yunxiang Zhao civil aviation Flight Technology and Flight Safety Research Base Civil Aviation Flight University of ChinaGuanghan618307China Airport Academy Civil Aviation Flight University of ChinaGuanghan618307China School of Economics and Management Civil Aviation Flight University of ChinaGuanghan618307China China Academy of civil aviation Science and Technology Beijing101300China Flight Training Standards Branch Civil Aviation Flight University of ChinaGuanghan618307China

With the development of the integration of aviation safety and artificial intelligence,research on the combination of risk assessment and artificial intelligence is particularly important in the field of risk management,but searching for an efficient and accurate risk assessment algorithm has become a challenge for the civil aviation ***,an improved risk assessment algorithm(PS-AE-LSTM)based on long short-term memory network(LSTM)with autoencoder(AE)is proposed for the various supervised deep learning algorithms in flight safety that cannot adequately address the problem of the quality on risk level ***,based on the normal distribution characteristics of flight data,a probability severity(PS)model is established to enhance the quality of risk assessment ***,autoencoder is introduced to reconstruct the flight parameter data to improve the data ***,utilizing the time-series nature of flight data,a long and short-termmemory network is used to classify the risk level and improve the accuracy of risk ***,a risk assessment experimentwas conducted to analyze a fleet landing phase dataset using the PS-AE-LSTMalgorithm to assess the risk level associated with aircraft hard landing *** results show that the proposed algorithm achieves an accuracy of 86.45%compared with seven baseline models and has excellent risk assessment capability.

关键词： Safety engineering risk assessment time series data autoencoder LSTM

Repair tolerance assessment for aircraft composite structures using Bayesian updating

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Chinese Journal of Aeronautics 2024年第6期37卷 360-391页

作者： Xin LI Hongfu ZUO Bin YANG School of Automotive and Rail Transit Nanjing Institute of TechnologyNanjing 211167China civil aviation Key Laboratory of Aircraft Health Monitoring and Intelligent Maintenance College of Civil AviationNanjing University of Aeronautics and AstronauticsNanjing 211106China

Detection and repair of composite damage is crucial to ensure the safety and reliability of aircraft structures.A novel approach to quantitatively evaluate the repair tolerance of composite structures in civil aircraft based on Bayesian updating is *** method incorporates historical damage inspection data to determine the prior distribution of damage size,which is then updated with newly collected damage size data using Bayesian *** Carlo simulation is employed to investigate the probability of failure and estimate maintenance costs,considering various factors such as the frequency and timing of damage events,damage detection,structural strength,gust loads,and maintenance expenses throughout the lifecycle of composite *** and economic factors are considered to establish a lower threshold for repairs and an upper threshold for maintenance based on the occurrence of accidental impact *** of the effectiveness and feasibility of a quantitative assessment method for repair tolerance is conducted using damage statistics data from civil aircraft routes utilizing the structural skin panels of composite outer *** results demonstrate that the method proposed in conjunction with extensive simulations and full utilization of field damage inspection data can effectively simulate unexpected impact damage situations that may occur during civil aircraft service and evaluate the reliability and economic feasibility of the repair of *** research findings hold significant theoretical and practical value for the preparation of documents for continued airworthiness of composite structures,including structural repair manuals and maintenance programs.

关键词： Composite structures Repair tolerance Maintenance Bayesian updating Probability of failure

The preparation and performance analysis of zirconium-modified aluminum phosphate-based high-temperature(RT-1500℃)resistant adhesive for joining alumina in extreme environment

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Journal of Advanced Ceramics 2024年第7期13卷 911-932页

作者： Jingxuan Liu Yange Wan Bo Xiao Jiancun Li Zhanming Hu Ruoyu Zhang Xiaoxia Hu Jiachen Liu Guoshuai Cai Hongli Liu Mingchao Wang College of Science Civil Aviation University of ChinaTianjin 300300China Department of Safety Engineering Civil Aviation University of ChinaTianjin 300300China Binzhou Beicheng Construction Engineering Materials Testing Co. Ltd.Binzhou 256602China Department of aviation Engineering Civil Aviation University of ChinaTianjin 300300China School of Materials and Engineering Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin UniversityTianjin 300072China

High-temperature-resistant adhesives are critical materials in the aerospace *** zirconium-modified aluminum phosphate-based adhesives developed in this work had the advantage of adjustable thermal expansibility,achieving a high matching of coefficient of thermal expansion(CTE)with *** introduction of zirconium can significantly improve the thermal stability of the adhesive matrix,and the Zr/Al ratio substantially affects the various reaction processes inside the adhesive,especially the types of zirconium-containing *** of the zirconium-containing compounds in the A7Z3 adhesive were ZrO2 only when the mass ratio of zirconium hydroxide to aluminum hydroxide was 3:7,which was the key reason why it had the highest *** room-temperature bonding strength of A7Z3 after heat treatment at 1500℃reached 67.2 *** pretreatment at 1500℃,the high-temperature bonding strength of A7Z3 was greater than 50 MPa in the range of(room temperature)RT-1000℃.After 40 thermal cycles between RT and 1500℃,the bonding strength still reached 10 *** bonding occurred at temperatures below 1000℃,while chemical bonding dominated above 1000℃based on the generation of Al5BO9 and mullite at the interfaces.

关键词： high-temperature-resistant adhesive thermal expansion property zirconium-modified aluminum phosphate bonding performance thermal cycling bonding mechanism

The Stokes-Einstein-Debye relation in ortho-terphenyl liquid

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Communications in Theoretical Physics 2024年第5期76卷 148-153页

作者：任淦 School of Science Civil Aviation Flight University of ChinaGuanghan 618307China

The Stokes–Einstein–Debye(SED)relation is proposed to be broken down in supercooled liquids by many ***,conclusions are usually drawn by testing some variants of the SED relation rather than its original *** this work,the rationality of the SED relation and its variants is examined by performing molecular dynamics simulations with the Lewis–Wahnstrom model of ortho-terphenyl(OTP).The results indicate the original SED relation is valid for OTP but the three variants are all broken *** inconsistency between the SED relation and its variants is analyzed from the heterogeneous dynamics,the adopted assumptions and approximations as well as the interactions among ***,care should be taken when employing the variants to judge the validity of the SED relation in supercooled liquids.

关键词： Stokes-Einstein-Debye relation Stokes-Einstein relation supercooled liquids Stokes'formula

Unsteady aerodynamic noise prediction of contra-rotating open rotor using meshless method

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Chinese Journal of Aeronautics 2024年第8期37卷 144-165页

作者： Zhiliang HONG Meng SU Haitao ZHANG Zerui XU Lin DU Lingfeng CHEN College of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China civil aviation Administration of China Beijing 100710China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

The Contra-Rotating Open Rotor(CROR)design confronts significant noise challenges despite being one of the possible options for future green *** efficiently estimate the noise emitted from a CROR,a three-dimensional unsteady prediction model based on the meshless method is *** unsteady wake flow and the aerodynamic load fluctuations on the blade are solved through the viscous vortex particle method,the blade element momentum theory and vortex lattice ***,the acoustic field is obtained through the Farassat’s formulation *** of this method is conducted on a CROR,and a mesh-based method,e.g.,Nonlinear Harmonic(NLH)method,is also employed for *** is found that the presented method is three times faster than NLH method while maintaining a comparable precision.A thorough parametric analysis is also carried out to illustrate the effects of rotational speed,rotor-rotor spacing and rear rotor diameter on the noise *** rotor speed is found to be the most influencing factor,and by optimizing the speed difference between the front and rear rotors,a notable noise reduction can be *** current findings not only contribute to a deeper comprehension of the CROR’s aeroacoustic properties but also offer an effective tool for engineering applications.

关键词： Contra-Rotating Open Rotor(CROR) Aerodynamic noise Blade element momentum theory Viscosity vortex particle method Farassat’s formulation 1A

Risk evaluation for the task transfer of an aircraft maintenance program based on a multielement connection number

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Frontiers of Engineering Management 2024年第1期11卷 16-31页

作者： Tao LIU Zhibo SHI Huifen DONG Jie BAI Yu YAN College of Electronics Information and Automation Civil Aviation University of ChinaTianjin 300300China College of Airworthiness Civil Aviation University of ChinaTianjin 300300China

This paper proposes a framework for evaluating the efficacy and suitability of maintenance programs with a focus on quantitative risk assessment in the domain of aircraft maintenance task transfer. The analysis is anchored in the principles of Maintenance Steering Group-3 (MSG-3) logic decision paradigms. The paper advances a holistic risk assessment index architecture tailored for the task transfer of maintenance programs. Utilizing the analytic network process (ANP), the study quantifies the weight interrelationships among diverse variables, incorporating expert-elicited subjective weighting. A multielement connection number-based evaluative model is employed to characterize decision-specific data, thereby facilitating the quantification of task transfer-associated risk through the appraisal of set-pair potentials. Moreover, the paper conducts a temporal risk trend analysis founded on partial connection numbers of varying orders. This analytical construct serves to streamline the process of risk assessment pertinent to maintenance program task transfer. The empirical component of this research, exemplified through a case study of the Boeing 737NG aircraft maintenance program, corroborates the methodological robustness and pragmatic applicability of the proposed framework in the quantification and analysis of mission transfer risk.

关键词： risk evaluation maintenance steering group analytic network process task transfer maintenance program

QAR Data Imputation Using Generative Adversarial Network with Self-Attention Mechanism

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Big Data Mining and Analytics 2024年第1期7卷 12-28页

作者： Jingqi Zhao Chuitian Rong Xin Dang Huabo Sun School of Computer Science and Technology Tiangong UniversityTianjin 300387China Institute of aviation Safety China Academy of Civil Aviation Science and TechnologyBeijing 100028China

Quick Access Recorder(QAR),an important device for storing data from various flight parameters,contains a large amount of valuable data and comprehensively records the real state of the airline ***,the recorded data have certain missing values due to factors,such as weather and equipment *** missing values seriously affect the analysis of QAR data by aeronautical engineers,such as airline flight scenario reproduction and airline flight safety status ***,imputing missing values in the QAR data,which can further guarantee the flight safety of airlines,is *** data also have multivariate,multiprocess,and temporal ***,we innovatively propose the imputation models A-AEGAN("A"denotes attention mechanism,"AE"denotes autoencoder,and"GAN"denotes generative adversarial network)and SA-AEGAN("SA"denotes self-attentive mechanism)for missing values of QAR data,which can be effectively applied to QAR ***,we apply an innovative generative adversarial network to impute missing values from QAR *** improved gated recurrent unit is then introduced as the neural unit of GAN,which can successfully capture the temporal relationships in QAR *** addition,we modify the basic structure of GAN by using an autoencoder as the generator and a recurrent neural network as the *** missing values in the QAR data are imputed by using the adversarial relationship between generator and *** introduce an attention mechanism in the autoencoder to further improve the capability of the proposed model to capture the features of QAR *** mechanisms can maintain the correlation among QAR data and improve the capability of the model to impute missing ***,we improve the proposed model by integrating a self-attention mechanism to further capture the relationship between different parameters within the QAR *** results on real datasets demonstrate that the model can rea

关键词： multivariate time series data imputation self-attention Generative Adversarial Network(GAN)