一种基于Aviator的公式定义及校验方法

在涉及数据采集、统计、分析的信息系统中,常常用到公式校验功能,来验证某些数据是否满足一定的公式条件,判定这些数据是否正确或合法。本文提出一种定义公式的数据模型,同时基于开源的Aviator,从公式校验步骤、公式子项求值两方面实现了公式的合法性及有效性校验,并在项目应用中实践成功。

2003款林肯Aviator

全新的2003款林肯Aviator是林肯品牌里的第一款中级尺寸的SUV,其特点是独特的设计和运动性能。林肯Aviator拥有更灵活多变的座椅配置方案,更大空间的座舱以及同级主中更突出的驱动能力,它欲在竞争日益激烈的中级SUV市场内分得一杯羹。

涅槃重生的豪华SUV 林肯Aviator飞行员

“飞行姿态”设计哲学 林肯Aviator采用最新的林肯家族设计语言,它的设计哲学成型于其命名,“飞行器所独有的流线型设计被用以打造全新林肯Aviator的外部线条.”林肯设计总监大卫 伍德豪斯表示.大尺寸进气格栅一眼望去和领航员有好几分相似,采用了全新航空学设计语言,更加符合它的名字“飞行员”的形象,与林肯LOGO相同形状的镂空设计也体现出了对于新车在细节上的极致追求.前大灯的造型棱角分明,内部两条LED日间行车灯设计也让其更具豪华感.

全新林肯飞行家Aviator

大型豪华SUV全新林肯飞行家Aviator于上海车展中国首秀。作为林肯SUV家族最新成员,全新林肯飞行家Aviator诠释林肯最新品牌理念'静谧之旅',将优雅设计及澎湃性能提升至新高度。它也是林肯品牌首个提供插电式混合动力选择的车型。

Deep ResNet Strategy for the Classification of Wind Shear Intensity Near Airport Runway

Intense wind shear(I-WS)near airport runways presents a critical challenge to aviation safety,necessi-tating accurate and timely classification to mitigate risks during takeoff and landing.This study proposes the application of advanced Residual Network(ResNet)architectures including ResNet34 and ResNet50 for classifying I-WS and Non-Intense Wind Shear(NI-WS)events using Doppler Light Detection and Ranging(LiDAR)data from Hong Kong International Airport(HKIA).Unlike conventional models such as feedforward neural networks(FNNs),convolutional neural networks(CNNs),and recurrent neural networks(RNNs),ResNet provides a distinct advantage in addressing key challenges such as capturing intricate WS dynamics,mitigating vanishing gradient issues in deep architectures,and effectively handling class imbalance when combined with Synthetic Minority Oversampling Technique(SMOTE).The analysis results revealed that ResNet34 outperforms other models with a Balanced Accuracy of 0.7106,Probability of Detection of 0.8271,False Alarm Rate of 0.328,F1-score of 0.7413,Matthews Correlation Coefficient of 0.433,and Geometric Mean of 0.701,demonstrating its effectiveness in classifying I-WS events.The findings of this study not only establish ResNet as a valuable tool in the domain of WS classification but also provide a reliable framework for enhancing operational safety at airports.

Ultra-Dense LEO Satellite-Aircraft Access and Service Management in Civil Aviation

With the deployment of ultra-dense low earth orbit(LEO)satellite constellations,LEO satellite access network(LEO-SAN)is envisioned to achieve global Internet coverage.Meanwhile,the civil aviation communications have increased dramatically,especially for providing airborne Internet services.However,due to dynamic service demands and onboard LEO resources over time and space,it poses huge challenges in satellite-aircraft access and service management in ultra-dense LEO satellite networks(UDLSN).In this paper,we propose a deep reinforcement learning-based approach for ultra-dense LEO satellite-aircraft access and service management.Firstly,we develop an airborne Internet architecture based on UDLSN and design a management mechanism including medium earth orbit satellites to guarantee lightweight management.Secondly,considering latency-sensitive and latency-tolerant services,we formulate the problem of satellite-aircraft access and service management for civil aviation to ensure service continuity.Finally,we propose a proximal policy optimization-based access and service management algorithm to solve the formulated problem.Simulation results demonstrate the convergence and effectiveness of the proposed algorithm with satisfying the service continuity when applying to the UDLSN.

Towards Greener Flying China develops sustainable aviation fuel for environmentally friendly air transport

At the 15th Airshow China,held in Zhuhai,Guangdong Province,from 12 to 17 November 2024,China Southern Airlines,in collaboration with the Global Sustainable Transport Innovation and Knowledge Centre and Airbus,presented a report on the development of sustainable aviation fuel(SAF).

Explosion damage effects of aviation kerosene storage tank under strong ignition

In order to study the blast damage effects of aviation kerosene storage tanks,the out-field explosion experiments of 8 m3fixed-roof tanks were carried out.The fragments,shock wave and fireball thermal radiation of the tank in the presence of bottom oil,half oil and full oil,as well as empty tank,were investigated under internal explosion by various TNT charge contents(1.8 kg,3.5 kg and 6.2 kg).The results showed that the tank roof was the only fragment produced,and the damage forms could be divided into three types.The increase of TNT charge content and oil volume enlarged the deformation of the tank,while the hole ratio presented a trend of increase first and then decrease.The H_r,maxand V_(max)values positively increased as increasing the TNT charge content and oil volume(from empty to half oil),but decreased in full oil.The Pmaxvalues had a progressive increase with the increment of TNT charge content,but not the case with the increase in oil volumes.The development of fireball was divided into three stages:tank roof‘towed'flame,jet flow flame tumbling and rising,and jet flow flame extinguishing.The Dmaxand Hf,maxvalues both increased as increasing TNT charge content and oil volumes.The oscillation phenomenon of fireball temperature was observed in the cooling process.The average temperature of fireball surface was positively correlated with TNT charge content,and negatively correlated with oil volumes.

Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics, astronautics and civil aviation.

Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics, astronautics and civil aviation.

Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.

Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics(TNUAA)is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronau-tics,astronautics and civil aviation.

Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community.Emphasizing prompt and effective dissemination of key data and new scientific insights,TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics, astronautics and civil aviation.

An Efficient Reliability-Based Optimization Method Utilizing High-Dimensional Model Representation and Weight-Point Estimation Method

The objective of reliability-based design optimization(RBDO)is to minimize the optimization objective while satisfying the corresponding reliability requirements.However,the nested loop characteristic reduces the efficiency of RBDO algorithm,which hinders their application to high-dimensional engineering problems.To address these issues,this paper proposes an efficient decoupled RBDO method combining high dimensional model representation(HDMR)and the weight-point estimation method(WPEM).First,we decouple the RBDO model using HDMR and WPEM.Second,Lagrange interpolation is used to approximate a univariate function.Finally,based on the results of the first two steps,the original nested loop reliability optimization model is completely transformed into a deterministic design optimization model that can be solved by a series of mature constrained optimization methods without any additional calculations.Two numerical examples of a planar 10-bar structure and an aviation hydraulic piping system with 28 design variables are analyzed to illustrate the performance and practicability of the proposed method.

Techno-economic and Environmental Assessments of SAF from Bioamss:An Review

This review presents a comprehensive techno-economic and life-cycle assessment of sustainable aviation fuel(SAF)production from biomass.The critical need for transitioning towards environmentally sustainable alternatives for liquid fuel and aviation industry is first discussed.Key insights encompass the evolutionary progression of biofuel production from first-generation to second-generation biofuels,with a focus on utilizing non-food sources like woody biomass for enhanced sustainability.Available data from the literature on techno-economic assessments of various SAF production pathways are analyzed including production costs,conversion efficiency,and scalability.Moreover,results of lifecycle assessments associated with different SAF production pathways are presented,providing essential insights for decision-making processes.The challenges of scaling up woody biomass-based SAF production are discussed based on the assessment results,and recommendations are proposed to steer stakeholders towards a greener and more sustainable trajectory for aviation operations.

Transactions of Nanjing University of Aeronautics and Astronautics Information for Contributors

Transactions of Nanjing University of Aeronautics&Astronautics (TNUAA) is a bimonthly journal facing international academic community. Emphasizing prompt and effective dissemination of key data and new scientific insights, TNUAA publishes experimental and theoretical papers bearing on applications to all branches of aeronautics,astronautics and civil aviation.

Effect of Nozzle Inclination Angle on Fuel-Air Mixing and Combustion in a Heavy Fuel Engine

Heavy-fuel engines are widely used in UAVs(Unmanned Autonomous Vehicles)because of their reliability and high-power density.In this study,a combustion model for an in-cylinder direct injection engine has been imple-mented using the AVL FIRE software.The effects of the angle of nozzle inclination on fuel evaporation,mixture distribution,and combustion in the engine cylinder have been systematically studied at 5500 r/min and consider-ing full load cruise conditions.According to the results,as the angle of nozzle inclination increases,the maximum combustion explosion pressure in the cylinderfirst increases and then it decreases.When the angle of nozzle incli-nation is less than 45°,the quality of the mixture in the cylinder and the combustion performance can be improved by increasing the angle.When the angle of nozzle inclination is greater than 45°,however,the mixture unevenness increases slightly with the angle,leading to a deterioration of the combustion performances.When the angle of nozzle inclination is between 35°and 55°,the overall combustion performance of the engine is rela-tively good.When the angle of nozzle inclination is 45°,the combustion chamber’s geometry and the cylinder’s airflow are well matched with the fuel spray,and the mixture quality is the best.Compared with 25°,the peak heat release rate increases by 20%,and the maximum combustion burst pressure increases by 5.5%.

Classification of aviation incident causes using LGBM with improved cross-validation

Aviation accidents are currently one of the leading causes of significant injuries and deaths worldwide. This entices researchers to investigate aircraft safety using data analysis approaches based on an advanced machine learning algorithm.To assess aviation safety and identify the causes of incidents, a classification model with light gradient boosting machine (LGBM)based on the aviation safety reporting system (ASRS) has been developed. It is improved by k-fold cross-validation with hybrid sampling model (HSCV), which may boost classification performance and maintain data balance. The results show that employing the LGBM-HSCV model can significantly improve accuracy while alleviating data imbalance. Vertical comparison with other cross-validation (CV) methods and lateral comparison with different fold times comprise the comparative approach. Aside from the comparison, two further CV approaches based on the improved method in this study are discussed:one with a different sampling and folding order, and the other with more CV. According to the assessment indices with different methods, the LGBMHSCV model proposed here is effective at detecting incident causes. The improved model for imbalanced data categorization proposed may serve as a point of reference for similar data processing, and the model’s accurate identification of civil aviation incident causes can assist to improve civil aviation safety.

Novel Method for Evaluating the Aging of Aviation Turbine Engine Oils via High-Temperature Bearing Deposit Tests

Aviation turbine engine oils require excellent thermal-oxidative stability because of their high-temperature environments.High-temperature bearing deposit testing is a mandatory method for measuring the thermal-oxidative performance of aviation lubricant oils,and the relevant apparatus was improved in the present study.Two different commercial aviation turbine engine oils were tested,one with standard performance(known as the SL oil)and the other with high thermal stability,and their thermal-oxidative stability characteristics were evaluated.After 100 h of high-temperature bearing testing,the SL oil was analyzed by using various analytical techniques to investigate its thermal-oxidative process in the bearing test,with its thermal-oxidative degradation mechanism also being discussed.The results indicate that the developed high-temperature bearing apparatus easily meets the test requirements of method 3410.1 in standard FED-STD-791D.The viscosity and total acid number(TAN)of the SL oil increased with the bearing test time,and various deposits were produced in the bearing test,with the micro-particles of the carbon deposits being sphere-like,rod-like,and sheet-like in appearance.The antioxidant additives in the oil were consumed very rapidly in the first 30 h of the bearing test,with N-phenyl-1-naphthylamine being consumed faster than dioctyldiphenylamine.Overall,the oil thermal-oxidative process involves very complex physical and chemical mechanisms.

A survey of composite robot for aviation intelligent manufacturing application

With the rapid development of the aviation industry,the development of intelligent manufacturing equipment represented by composite robots has been paid close attention by the aviation industry.Based on the analysis of the background and main structure function of composite robots,this paper focuses on the analysis of key technologies such as composite robot hardware design,visual sensing and planning system,integrated control of‘hands,feet,and eyes',multi-robot collaborative operation,and safety.The typical applications of composite robots in aviation intelligent manufacturing such as automatic drilling and connection of aircraft,aircraft surface spraying and finishing,parts handling,aircraft measurement,and inspection are presented.The development trends such as standardization of composite robots,integration of‘5G+cloud computing+AI',and fusion of intelligent sensors are proposed.