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

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 industry.Therefore,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 labels.Firstly,based on the normal distribution characteristics of flight data,a probability severity(PS)model is established to enhance the quality of risk assessment labels.Secondly,autoencoder is introduced to reconstruct the flight parameter data to improve the data quality.Finally,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 assessment.Thus,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 events.The results show that the proposed algorithm achieves an accuracy of 86.45%compared with seven baseline models and has excellent risk assessment capability.

Construction and Application of Knowledge Graph for Quality and Safety Supervision of Transportation Engineering

Knowledge graph technology play a more and more important role in various fields of industry and academia.This paper firstly introduces the general framework of the knowledge graph construction,which includes three stages:information extraction,knowledge fusion and knowledge processing.In order to improve the efficiency of quality and safety supervision of transportation engineering construction,this paper constructs a knowledge graph by acquiring multi-sources heterogeneous data from supervision of transportation engineering quality and safety.It employs a bottom-up construction strategy and some natural language processing methods to solve the problems of the knowledge extraction for transportation engineering construction.We use the entity relation extraction method to extract the entity triples from the multi-sources heterogeneous data,and then employ knowledge inference to complete the edges in the constructed knowledge graph,finally perform quality evaluation to add the valid triples to the knowledge graph for updating.Subgraph matching technology is also exploited to retrieve the constructed knowledge graph for efficiently acquiring the useful knowledge about the quality and safety of transportation engineering projects.The results show that the constructed knowledge graph provides a practical and valuable tool for the quality and safety supervision of transportation engineering construction.

The Analysis of Human Behaviour and Evacuation in a Fire Situation in a Building for Higher Education

The paper presents the analysis of a human evacuation from a higher education building located in Iassy,Romania,by means of engineering techniques to approach fire safety.Because in Romania(as in other European countries)fire safety design of buildings is prescriptive and not performance-based,a fire safety engineering approach arouse great interest in many countries such as the U.S.A.,Australia,New Zealand,England,Sweden,Finland,etc.This paper is based on the assumption of starting a fire in the space of a hall for festivities,located on the ground floor of the building,near two human evacuation routes;We consider two building evacuation scenarios:two exits and,respectively,just one exit(assuming that the second would be accidentally blocked).

A New Safety Electric Initiating System

Based on the analysis of weakness on the safety of traditional electric detonators, a BJ-l safety electric detonator initiatingsystem and its corresponding safe examination technique were successfully developed. By leading false foot wires and taking advantageof the transmitting frequency band of Mo-Zn ferrite, detonators in this new system can completely impede the direct induction of outsidecrosstalk that may cause casual firing in the ordinary as well as eleclromagnetic ones. Possible causality by lightning was discussed. Results are presented, of its safety tests on resistance to direct and alternating current, electrostatic, and crosstalk induced by damp leakagein saturated salty water.

Research on Distribution Regularities of Dust Concentration and Granularity in Large Mining Height Working Face

The key for dust control of coal mine is to clarify the dust concentration distribution and sedimentation in different areas. Both similarity experiment and numerical simulation method have certain restrictions and are quite different from the actual situation on site. In order to study the dust sedimentation regularity of coal mine in large mining height, “filter membrane method” is adopted in this paper, i.e., to dry and weigh the filter membrane before and after sampling, collect the dust of respirable zone on mining face and calculate the dust concentration based on a main airway of 100 m. The result shows that: A large amount of dust will be produced during coal mining, wherein the maximum dust concentration from 6 m upstream to 100 m downstream of coal cutter is 121 mg/m3, while the minimum dust concentration is 61 mg/m3;The dust concentration in return airway is reduced with the distance increases, while the dust concentration at the entrance is 91 mg/m3;A large amount of dust may fall from roof during section advancing and improves the dust concentration of hydraulic support in walking area obviously;The dust granularity of mining face and return airway is 0 - 100 μm, but the amount of respirable dust is higher than 80%, the larger the dust particle size, the higher the dust concentration. Besides, dust in small particle size can be suspended in air flow for longer, but that in large particle size may subside under the action of gravity;To reduce dust exposure, the mining position shall be located in the windward direction of advancing or coal cutter. This research can provide guidance for taking dust prevention measures of working face in large mining height.

Numerical Analysis of Surcharge Effect on Stability and Interaction Mechanism of Slope-Pile-Footing System

To investigate the stability and interaction mechanism of the slope-pile-footing system under surcharge effects,the finite difference method(FDM)was adopted to analyze the response laws of the stability of the reinforced slope,evolution of the critical slip surface,stress characteristic of retaining structures,deformation and failure modes of the slope foundation and building footing under surcharge parameters,including the surcharge intensity,the surcharge position,and the surcharge width.The results show that surcharge parameters significantly affect the stability and the deformation characteristics of the slope-pile-footing system.Specifically speaking,with the increasing surcharge intensity and the decreasing surcharge position and width,the deformation and failure mode of the system will gradually evolve in a direction that is harmful to its stability.The interaction mechanism of the slope-pile-footing system is further clarified as the load transfer of the building footing,the generation of the additional stress in the slope foundation,and the adjustment of pile bending moment due to the stress redistribution.Correspondingly,the safety of anti-slide piles will determine the stability of the slope foundation and building footing.These findings are expected to provide guidance for the comprehensive development and utilization of filled slopes after reinforcement.

Safety Analysis of Flow Parameters in a Rotor-stator Cavity

In order to ensure the safety of engine life limited parts （ELLP） according to airworthiness regulations, a numerical approach integrating one-way fluid structure interaction （FSI） and probabilistic risk assessment （PRA） is developed, by which the variation of flow parameters in a rotor-stator cavity on the safety of gas turbine disks is investigated. The results indicate that the flow parameters affect the probability of fracture of a gas turbine disk since they can change the distribution of stress and temperature of the disk. The failure probability of the disk rises with increasing rotation Reynolds number and Chebyshev number, but descends with increasing inlet Reynolds number. In addition, a sampling based sensitivity analysis with finite difference method is conducted to determine the sensitivities of the safety with respect to the flow parameters. The sensitivity estimates show that the rotation Reynolds number is the dominant variable in safety analysis of a rotor-stator cavity among the flow parameters.

Blade containment evaluation of civil aircraft engines

The potential hazard resulting from uncontained turbine engine rotor blade failure has always been the long-term concern of each aero engine manufacturer, and to fully contain the failed blades under critical operating conditions is also one of the most important considerations to meet the rotor integrity requirements. Usually, there are many factors involving the engine containment capability which need to be reviewed during the engine design phases, such as case thickness, rotor support structure, blade weight and shape, etc. However, the premier method to demonstrate the engine containment capability is the fan blade-off test and margin of safety （MS） analysis. Based on a concrete engine model, this paper aims to explain the key points of aero engine containment requirements in FAR Part 33, and introduces the implementation of MS analysis and fan blade-off test in the engine airworthiness certification. Through the introduction, it would be greatly helpful to the industrial community to evaluate the engine containment capability and prepare the final test demonstration in engine certification procedure.