bluuebunny/crossref_metadata_2025 huggingface dataset:
A Survey on Software Reliability Demonstration
Authors: He Wei , Ding Jianyang , Shen Xiaomei , Han Xinyu , Tang Longli
Published: February 2021

Software reliability demonstration is the process of making scientific decisions on the development and management of software through logical reasoning with sufficient evidence and rigorous methodology. It is the first and foremost task in software reliability engineering. There is much literature on various aspects that aim to facilitate software reliability demonstration. In this paper, we provide an overview of the related concepts, principles, activities, standards and techniques. Besides, we discuss key issues that are pertinent to software reliability demonstration and presents directions for future research.
Identifying Safety Performance Indicators for Risk Assessment in Civil Aviation
Authors: Chen M , Chen Y , Ma S
Published: February 2021

Safety is particularly important for civil aviation because civil aviation accident will result in serious casualties and property losses. As a core element of safety management system, safety performance management plays a more and more important role in improving safety management efficiency of service providers. A systematic establishment process of safety performance indicator system is presented. A novel risk assessment model of a department is proposed based on four types of safety performance indicators identified by system and job analysis, event tree analysis, fault tree analysis, bow-tie, and so on. A case study of risk assessment using the proposed model is presented for two departments in an airport which implements safety performance management. The results illustrate the operation risk of different departments can be assessed based on safety performance indicator system.
Research and Analysis of Software Defect Measurement Elements Based on Analytic Hierarchy Process
Authors: Xu Z W , Wu L J , He R Y , Han X Y , Tang L L
Published: February 2021

It is not convenient for the general software quality evaluation system to be directly and quickly applied to the software quality evaluation to be tested. Therefore, this paper proposes a method suitable for the analysis of factors affecting software quality based on analytic hierarchy process. The analytic hierarchy process is used as the main framework, the distribution of the software’s own properties and accumulated test findings as input,the constructed defect weight ratio is used as the judgment matrix, Then do the hierarchical analysis. Through the analytic hierarchy process to analyse the weight of the factors of the software itself, test organizations can quickly make a fuzzy assessment of software quality, and provides the reference basis for the reasonable allocation of test resources.
Fault prediction method of analog circuits based on MLSTM
Authors: Fan Hui , Hu Weiwei , Si Tianyu , Sun Yufeng
Published: February 2021

According to statistics, most of the electronic equipment fault cases are related to the analog circuit, which may lead to the failure of the whole system due to the drift or performance degradation of the parameters of an electronic component in the analog circuit. However, because of the continuity of the parameters of each component, the lack of test nodes and the nonlinearity problems, the analog circuit becomes more difficult to prognose. The fluctuation and inconspicuousness of the degradation trend in analog circuits lead to the difficulty in extracting characteristic parameters and low accuracy of fault prediction. Therefore, a fault prediction method for analog circuits based on Multi-scale and Long-Short Term Memory (MLSTM) is proposed in this paper. Multi-scale feature learning method can divide the original data into different scales to improve the learning accuracy of small sample data. LSTM can well identify the temporal sequence of the widely separated events in the noise input stream. In this paper, the multi-scale feature learning method is combined with LSTM to improve the accuracy of fault prediction. Finally, the DC-DC switching power supply is taken as a case for verification, and the proposed method is compared with other algorithms to verify its accuracy and applicability.
Research on Availability Model of Two-dimensional Warranty Products Based on Incomplete Maintenance
Authors: Wang Rongcai , Cheng Zhonghua , Wang Qian
Published: February 2021

In view of the problem that the availability of two-dimensional warranty products is difficult to meet the actual needs of users during the warranty period, on the basis of incomplete preventive maintenance, this paper uses the accelerated failure time (AFT) model to describe the failure rate form of products, constructs the two-dimensional warranty product availability model and gives an effective solution. On this basis, taking the maximum availability of two-dimensional warranty products as the optimization objective, the optimal preventive maintenance interval and warranty period optimization scheme are calculated. Finally, the validity and accuracy of the model are verified by an example, which provides a scientific basis for manufacturers to formulate two-dimensional product warranty strategy.
Overview of Laser-Based Inspection Technology
Authors: Wang Qun , Pan Juan , Gao Guilong , Yao Dong
Published: February 2021

High-precision detection of structural state information and long-term monitoring of its operation process are the basic tasks that support the assessment of safety and reliability. Compared with methods such as sampling and testing, nondestructive testing does not damage the structural integrity, which has been the focus of research in recent years. Based on the demand for structural condition monitoring in the engineering field, this article has combed traditional non-contact monitoring technologies such as air-coupled ultrasound, and analyzed its working mode, technical characteristics, and application characteristics; around the non-contact characteristics of laser ultrasound technology, its excitation effect, Feedback picking, etc. were discussed. Finally, combing the technical characteristics and application basics, some suggestions for follow-up key research are put forward.
Research on the application of on-line monitoring technology for bolt axial force of wind turbine
Authors: Cao Linlin , Liu Kai , Zhang Zhongwei , Sun Wendong , Chen Weiliang
Published: February 2021

During wind turbine operation, hub and pitch bearing connection bolts are constantly subject to alternating loads. The axial force of the bolts is an important factor affecting the normal operation of the wind operation. Real-time monitoring of residual axial force can timely feedback the operation of the wind turbine and then the health assessment of the fan structure can be realized. This paper introduces a monitoring system of axial force based on ultrasonic method for measuring bolt axial force. The system can realize the data acquisition of multiple bolts and multiple measuring points in the period. Then, we introduce the engineering application of the system and the corresponding data management system. Through the analysis of the monitoring data, scientific and accurate maintenance of the connection structure is realized, which reduces the operation cost and quality cost. This paper also tests the adaptability of the system to verify its accuracy and reliability at different temperatures.
Prediction of magnitude data of multi-channel vibration on a vehicle platform environment
Authors: Zhu Yu-Qin , Wang Cheng-Zhang , He Jian-Xin , Li Jia-Meng , Wu Shuai , Li Di-Fan
Published: February 2021

The vibration prediction model of the key vibration source points of a vehicle platform is studied. Starting from the analysis of the factors affecting the vibration response and the correlation analysis, the key factors affecting the vibration response of the same vehicle structure are sorted out. The vibration prediction model of the key vibration source points is established by using neural network, and using the measured data to verify the accuracy of the vibration prediction model of the cabin section I, cabin II and cabin III of the platform. The results show that in the frequency range of 1∼500Hz, the maximum error of root mean square of cabin I is 2.75dB, that of cabin II is 2.3dB, and that of cabin II is 2.97dB.
Influences of cutting parameters on surface roughness of SiCp/Al composites
Authors: Wang J L , Huang S T , Pang B , Li H B
Published: February 2021

Poor surface roughness may reduce the safety and the stability of the parts, to analyse the relationship between cutting parameters and surface roughness is significative to increase the machining quality of SiCp/Al composites. In this paper, the influences of tool rake angle, cutting speed and cutting depth on the surface roughness of SiCp/Al composites were studied by the two dimension cutting experiments. The Ra values were measured by using type TR200 roughness machine. The results indicate that tool rake angle and cutting depth are the main parameters which affect the surface roughness while cutting speed has no significant effects on the surface roughness.
Fault diagnosis for mechanical system using dynamic Bayesian network
Authors: Pang Tian Yang , Yu Tian Xiang , Song Bi Feng
Published: February 2021

The present study focuses on the fault diagnosis of mechanical systems. Mechanical systems are considered with interconnected components that work together to achieve a common function or purpose. On the one hand, the fault diagnosis result is affected by strong dependence between each component. One the other hand, diagnostic results may be different at different time slices because of the performance degradation of components when the same fault symptoms are given. To deal with these problems in diagnosis, a dynamic Bayesian network (DBN) model is proposed. First, series and parallel systems are converted to a Bayesian network. And the relationship between components and reliability of the system is expressed by the Bayesian network. Then, the dynamic Bayesian network is established to model the dynamic degradation of components in a system under additional information by using the wear data. The parameters of the model are estimated by historical data. Finally, a case is investigated to verify the proposed model in this study. Fault diagnosis is conducted through a backward analysis of the DBN model proposed, and the weakest component is identified. The dynamic probabilities of the mechanical system are obtained through forwarding analysis of the DBN model.
Damage localization in composite plates that exploits edge-reflected Lamb waves
Authors: Zhang Ying , Wang Jianguo , Zeng Liang
Published: February 2021

Lamb waves can travel a relatively long distance in the plate-like structures. Reflection and scattering may occur when they arrive at an obstacle, and the associated wave packets may contain the information about the obstacle and the whole path they travel through. Those extra reflections change the direction once they meet an obstacle, which enlarges the monitoring zone and enriches the inspecting directions. The motivation and objective of this paper is to exploit the information included in these reflections for damage identification. Firstly, dispersion compensation is applied to the residual between the measured signal and the pre-recorded baseline. Thus the propagation distance of each scattered wave packet could be estimated. On this basis, the sparse reconstruction algorithm is modified to adapt to both direct-scattered waves and indirect-scattered waves for damage identification. Two experimental examples are conducted on CFRP laminates, where damage is correctly identified with the minimum sensor array consisting of one transmitter and one receiver.
Influence of a local defect on the cage vibrations for a ball bearing
Authors: Li Shenlong , Jiang Yanhong , Xu Yajun , Liu Jing
Published: February 2021

Impacts will occur when the balls pass through the local defect. The cage vibrations can be affected by the impacts, which may influence the steady state of ball bearing system. Thus, the relationship between defect size and the cage vibrations can be helpful for ascertaining the mechanisms of the cage vibrations. In this paper, a multi-body dynamic model of a ball bearing with a local defect is proposed by using the multibody commercial software. Effects of the defect sizes and inner ring speed on the angular velocity of the cage are studied. The relationship of the contact forces between the balls and bearing components are discussed too. The results show that the multi-body dynamic model can be applied to study the cage vibrations for a defective ball bearing.
An Improved Detection Algorithm of Three-phase Unbalanced Voltage Sag Detection Method for Improving Power Supply Reliability
Authors: Peng C , Hu S L , Hao X H
Published: February 2021

With the popularization of high-power power electronic switching equipment and the technical update of electrical equipment, voltage sags have become a major problem affecting power quality, which seriously affects the reliability of power supply in power systems. In the case where the voltage sags failure cannot be avoided, rapid and accurate detection of the voltage sag has become a key technology for improving the reliability of the power supply of the power system. Based on the symmetrical component method, an improved detection algorithm for three-phase unbalanced voltage sag is proposed in this paper, which can significantly improve the detection speed and the reliability of power supply. The method firstly constructs the virtual orthogonal signal of the grid voltage and uses the symmetric component method to realize the fast and accurate extraction of the positive and negative sequence components of the grid voltage fundamental. In addition, an improved method for constructing virtual orthogonal signals is proposed in this paper, which effectively improves the accuracy of the constructed orthogonal signals. Finally, the feasibility and priority of the improved detection method have been verified by MATLAB/Simulink.
Truncated Sequential Sampling Plans of Electrical Products Having Two Failure Modes
Authors: Yang Xinyu , Chen Guangyu , Tang Ling , Wang Ruiqi , Wu Jie , He Fu , Liang Na
Published: February 2021

It is of great significance to design an economic sampling plan for the electrical products in mega engineering projects. The existing traditional plan normally considers single failure mode of the item being inspected. However, the major products in mega engineering projects usually have different failure modes. To overcome the drawbacks of traditional plans, a truncated sequential sampling plan of electrical products having two failure modes is proposed in this paper. The newly proposed sequential sampling plan takes two different failure modes of an electrical product into consideration, consisting of the sequential sampling scheme for soft-failure mode and the sequential sampling scheme for catastrophic-failure mode. The concept of cut-off line is introduced, limiting the sample size within a certain range. At last, a numerical example is provided. This newly proposed sequential sampling plan provides a reference for the design of economic acceptance sampling plans for expensive electrical products and the products with multi-failure modes.
The Epidemic Prediction of Coronavirus disease 2019 Based on a SEIR(Susceptible-Exposed-Infected-Removed) Model Considering Population Migration between Wuhan and other Provinces in China
Authors: Wang Anran , Zhan Ruobing , Yu Fen , Mi Jie , Gao Kaiye
Published: February 2021

As the first city detected the novel coronavirus in China, Wuhan was quarantined since Jan 23, 2020. The measure effectively prevented the epidemic spreading between provinces in China. This article proposes the SEIR infectious disease dynamics model introduced the inter-provincial migration factor, which is called the SEIRM model. The proposed model analyses the epidemic situation of 7 kinds of people when they can migrate freely between Wuhan and other provinces in China. Using the proposed model, we predict that until March 1st, 2020, the top five most severely epidemic-affected provinces are Hubei Province, Guangdong Province, Henan Province, Hunan Province, and Jiangxi Province; it is also predicted that more than 60.25 million people will be infected and approximately 837 thousand people will die due to this epidemic, which will exceed the medical resources load in China. According to our results, the population migration during the Spring Festival will quickly lead to a large-scale epidemic outbreak in China, which implies that locking down Wuhan and quarantine measures nationwide have a positive effect on China’s epidemic prevention. Epidemic prevention measures will effectively prevent the spread of the epidemic, quickly restore social and economic order, and protect the health of the people of the country.
Test-system design for hydraulic solenoid valve of a certain aircraft
Authors: Zai-Qing Ren , Jian-Hui Wang
Published: February 2021

Based on the test requirement of hydraulic solenoid valve (YDF-16) of a certain aircraft, the test-system of YDF-16 is designed. The test-system consists of a pneumatic unit, a control measure unit and a software unit. It can be used to test the performance parameter of the YDF-16. The test-system is fulfilled the needs of aircraft repair factories and achieves good results in application.
Evaluation of Aerospace Production Site Management and Control Capability based on F-AHP and BP Neural Network
Authors: Jia Fengsheng , Li Hui , Lai Rui , Yao Hongtao , Bao Zhiwen
Published: February 2021

The management and control level of aerospace production site directly affects the production quality of aerospace products. It is one of the important fields of aerospace quality management research to master the management and control ability of aerospace production site efficiently. Based on the analysis of the control scope of aerospace production site, the evaluation index system of space production site control ability is proposed. Through the establishment of Fuzzy-Analytic Hierarchy model, the sample data of process management and control ability evaluation on aerospace production site was collected. BP neural network model was constructed and trained, the output of BP neural network reached the expected accuracy, which meet the requirements of process management and control ability evaluation on aerospace production site. The result shows that the proposed evaluation index system and BP neural network model can not only fully absorb the tacit knowledge of experts, but also reduce the subjective arbitrary defects of artificial weights, which can be used to evaluate of the control ability of aerospace production site efficiently.
Extraction and utilization of satellite products life and reliability data on orbit
Authors: Lv Xinqi , Wang Jingyan , Du Nan
Published: February 2021

Based on the analysis and carding of the reliability and life parameters of satellites, the paper sorted out the on orbit reliability features of various types of satellite products according to the basic concept of reliability. Further, the paper put forward the basic method of reliability feature extraction based on satellite telemetry data. On this basis, the on orbit reliability database of satellite products is designed, which effectively realizes the classified storage and management application of on orbit reliability related information, and provides support for the following on orbit reliability data on orbit life prediction, reliability evaluation and other aspects of utilization.
The wheel-step planetary exploration vehicle with two-way stable obstacle-crossing function
Authors: Zhang Sijia , Yao Jie , Fu Lanting
Published: February 2021

Planetary exploration has always been an important topic in China’s aerospace field. On the rugged planet surface, having a good obstacle-crossing ability is crucial to the mission of the planetary exploration mobile system In this paper, after consulting the data of planetary vehicles at home and abroad, and analyzing the current suspension structure of wheeled planetary exploration vehicles at home and abroad, a six-wheel planetary exploration vehicle with a certain obstacle-crossing capability and capable of bidirectional driving is designed.
Prediction of Spindle Rotation Error through Vibration Signal based on Bi-LSTM Classification Network
Authors: Liang Jianhong , Wang Liping , Wu Jun , Liu Zhigui , Yu Guang
Published: February 2021

One of the important indexes for high-precision machine tools is spindle rotation error, which is closely related to mechanical processing product quality. However, it’s difficult to directly acquire rotation error in the actual machining process. This literature proposed a novel uncompressed approach to predict spindle rotation error through vibration signal based on Bi-LSTM classification network, and this approach mainly consists of three steps, namely, pretreating original data; training Bi-LSTM classification network; predicting spindle rotation error. This approach adopts an uncompressed vibration signal method, which retains the time characteristic information into the predicted network, to build the relationship between easily collected vibration signal and the spindle rotation error. Finally, the proposed approach is applied in a spindle test rig, which has accomplished over 1700 hours of simulated load abrasion, and collected 170 days’ vibration signal and corresponding rotation error at RPM=1000, 2000, 3000, and 4000 conditions. The results show the proposed approach can effectively predict the spindle rotation error.
Flight Reliability Assessment of Assisted Torpedo Based on Probabilistic Risk Assessment
Authors: Wang Xinpeng , Feng Tong , Meng Bo
Published: February 2021

In this paper, a reliability assessment method based on probabilistic risk assessment is proposed to solve the difficulty in the flight reliability evaluation of assisted torpedo. An event chain model is established through the analysis of missions and functions. The relationship between functional events and mission process reliability is described on the basis of event tree. The relationship between component reliability and functional event reliability is analyzed on the basis of fault tree. For the uncertainty of component failure probability, triangle fuzzy number is used to describe the interval representation of component failure probability, and fuzzy fault tree is used to represent the reliability of each functional event. The reliability of the entire flight process is comprehensively evaluated to obtain a realistic flight torpedo flight reliability assessment result.
Prediction model of aeronautics equipment spare parts considering spare part sharing
Authors: Yanluo Geng
Published: February 2021

A prediction method of aeronautics equipment spare parts requirement considering spare part sharing was proposed aimed at reducing high spare parts sharing proportion of similar types of aeronautics equipment. Firstly, according to the structural similarity, the spare parts were divided into special spare parts and shared spare parts. Then, the spare parts requirement under the condition of daily support and wartime support was further considered. With the constraint of spare parts support probability, the requirement prediction model of special spare parts and shared spare parts were constructed respectively on the basic assumption that the daily failure obeyed the exponential distribution and the battle damage-oriented obeyed the binomial distribution. Finally, based on a certain kind of avionics system, the validity and effectiveness of the proposed model were verified.
Research on the Early Warning Method of Water Delivery Pipeline Detonation Based on High-frequency Water Pressure Monitoring
Authors: Xinmin Zhu , Tianxiang Lin , Shaokong Feng , Feng Shang , Zhe Fan
Published: February 2021

In order to study a novel monitoring method suitable for pressure water conveyance project, the fiber grating pressure sensor was adopted for monitoring the water pressure of in-service glass fiber reinforced plastic mortar pipeline. An emptying valve was used in the prototype test to simulate the leakage process and the dynamic water pressure process was recorded effectively by the fiber grating pressure sensor with high frequency and high precision. According to prototype test results, a fluctuation analytical method was proposed, which uses random average pressure as the equilibrium standard value. Meanwhile, an early warning system against pipe failure was developed based on this method. The system was verified by the simulated leakage tests, and the results show that the system could alarm the leakage of more than 0.25% of pipeline design flow, and the positioning accuracy was 10 m–20 m.
An access control model based on matrix domain security label
Authors: Liqing Li , Hai Lu
Published: February 2021

The large complex organization that needs to strictly implement the ‘Need to Know’ secure principle should establish a multi-level security information identification and access control mechanism. In this paper, it proposes that a large-scale complex organization is a matrix structure; hence, a matrix security label that conforms to the characteristics of the matrix domain shall be established. On the basis of RBAC and MLS Model, this paper supplements the definitions of security label and necessary constraints, and thus forms an improved access control model.
Effect of temperature on natural frequencies of bridge structure of metallurgical crane
Authors: Zhao L , Jin H
Published: February 2021

It is an important prerequisite for structural design and structural health monitoring to accurately obtain the natural frequencies and modal shapes of the structures, however, which are not only related to the stiffness and mass of the system itself but also affected by temperature, humidity, load and other factors. Therefore, the effect of environmental factors on the dynamic parameters of the structures should not be ignored in the process of dynamic analysis, especially for the structures which run in the complex environment such as bridge structures of metallurgical cranes. In this paper, two physical fields of solid heat transfer and solid mechanics in COMSOL are used to analyse the dynamic parameters of the bridge structure of a double-beam bridge crane based on the consideration of temperature effect and neglect of temperature effect respectively. The results show that, without considering the influence of ambient temperature on the material of crane bridge structure, whether the temperature effect is taken into account or not has no obvious effect on the form of structural vibration modal shapes. In addition, it can be concluded that the natural frequencies of each stage of crane -bridge structure increase under the condition of considering the influence of service ambient temperature, and the increase of natural frequencies of each stage also increases with the increase of convection air temperature at the bottom of the lower cover plate of the main beam.
Analysis of Uneven Settlement of Large Oil Storage Tank
Authors: Yunxiu Ma , Jian Li , Keqin Ding , Jiwang Zhang
Published: February 2021

The uneven settlement of large oil storage tank will not only cause the tank wall to be elliptical and the upper floating plate to be blocked, but also cause the tank body to fall. In order to study the influence of uneven settlement on the tank structure, this paper takes 50000m3 oil storage tank as an example, uses the finite element simulation method to explore the influence of uneven settlement of different scales of large tank foundation on the overall stress characteristics of the tank, and obtains the storage. The influence of uneven settlement of tank foundation on the mechanics of tank body, tank bottom and large corner joint. It can provide some guidance for tank management and evaluation.
Research on comprehensive evaluation of quality performance of all employees in electronic equipment enterprises based on entropy method and ideal point method
Authors: Zhou Yong , Qin Jian
Published: February 2021

The overall quality evaluation of electronic equipment is helpful to improve product quality and has become an important focus of quality control. Based on the systematic analysis of job characteristics of all employees, sixteen index frames are constructed from four dimensions of knowledge quality, key quality performance, quality reward and punishment and quality innovation. Secondly, the fuzzy value conversion method is designed with the characteristics of the evaluation index value of electronic equipment, the objective weight is determined by the entropy method, and comprehensive evaluation model is also designed by ideal point method. Finally, a case is given to illustrate the implementation process and feasibility of the proposed method, which can provide theoretical and practical guidance for improving quality performance of all employees.
Research on comprehensive evaluation of six “properties” for equipment products incorporating correlate indexes
Authors: Qin Jian , Mei Wenhui , Zhou Yong
Published: February 2021

The six “properties” for equipment products are critical indexes to improve the quality of equipment development and batch production. In view of current difficulties of auditing six “properties” and putting qualitative or quantitative evaluation into practices, this paper analyses interactive characteristics of six “properties” and organically integrates them based on the VIKOR method. Firstly, the indexes and connotation of six “properties” for equipment products have been elaborated. Secondly, specific relationship among six “properties” is analysed and their interactive coefficients are depicted as two additive fuzzy measures. Thirdly, the effect of interactive coefficient among six “properties” is analysed on group utility and individual regret in the VIKOR method, and specific decision-making steps based on the VIKOR method are also proposed. Finally, two illustrative cases show the differences of multiple indexes decision results under two kinds of conditions and the feasibility and effectiveness of the proposed methods.
Study on the Reliability of Mechanical Components of Squib Valve in Passive Nuclear Power Plant
Authors: Qiang Liu , Lechang Zhan , Xiaowei Zhang , Liangming Chang , Jingxian Ma , Xihui Su
Published: February 2021

The action principle of squib valve employed in passive nuclear power plant was introduced and the main factors affecting the reliability of the mechanical components of the squib valve were analyzed, and the shear cover material of the squib valve was subjected to different strain rates at normal temperature, 155 °C and 350 °C, The parameter distribution of Johnson-Cook constitutive model was obtained by fitting the test data, and the impact velocity, material properties and failure strain of the squib valve piston were selected as random variables, and the reliability of the mechanical components of the squib valve was calculated by the joint simulation of ABAQUS+NESSUS. The results show that the reliability of the squib valve is high, and the mechanical performance of the shear cap material is the biggest impact on the mechanical reliability of the squib valve. The mechanical reliability of the squib valve is positively related to the impact speed of the piston. This study provides a reliable basis and reference for quantitative assessment of the overall reliability of the squib valve and the application in passive nuclear power plant.
Environmental Adaptability Assessment of FiberReinforced Composites based on Fuzzy Comprehensive Evaluation Method
Authors: Chen Y , Huang H Z , Qiao Z P , Yang W J , Chen X H , Luo D , Qin Y J , Wu S
Published: February 2021

The environmental adaptability of fiber reinforced composites is affected by different environmental factors. By recording the environmental factors parameters and performance parameters related to the test environment, the main parameters affecting the material properties are obtained by gray correlation analysis on the environmental factors parameters; the main environmental factors affecting the material performance are selected, and the weight of environmental factors is determined by AHP According to the characteristics of environmental factors, a membership function is constructed to evaluate the environmental adaptability of materials when the main parameters of environmental factors are known. At the end of this paper, the effectiveness of the environmental adaptability evaluation method is verified by the test results of similar fiber reinforced composite materials.
Study on Acoustic Radiation Calculation and Far Field Criterion of Oil pan
Authors: Huang Yue-zhen , Zhang Bo , Zhao Ke-lun , Xia Xue-bao
Published: February 2021

Diesel engine with low vibration and noise characteristics will be a major trend for the future development. As the shell part on the engine, the vibration and noise control of the oil pan is an urgent problem to be solved. It is of practical significance to predict the oil pan vibration and radiation noise during the design phase. An oil pan of diesel engine was taken as the research object, the finite element model of the oil pan was established and the finite element method (FEM) was used to calculate the oil pan vibration response. Three different numerical calculation methods (Finite element-boundary element hybrid method, finite element-infinite element hybrid method, finite element-automatic matching layer technology) were used to calculate radiated sound power level of the oil pan respectively. The calculation accuracy and efficiency of three different calculation methods were compared and analyzed. The results show that the finite element-boundary element method is more suitable for the calculation of the acoustic radiation of the oil pan. Finally, a method based on the directivity of acoustic radiation to determine the far-field acoustic radiation is proposed and verified.
Development of reliability testing device for grating encoder
Authors: Zhou Xin-Da , Chen Chuan-Hai , Tian Hai-Long , Yang Hai-Ji , Li Shi-Zheng
Published: February 2021

The technical index of a reliability testing device for grating encoder is determined based on the analysis of the working condition and fault cause of the grating encoder, and the overall scheme of the test device is designed. The support and mechanical structures of the operation fixture and loading device and the monitoring system of the test device are designed based on a modular design. The upper computer software is developed using LabVIEW, and the programming frame and the control interface are introduced. Reliability test is performed to verify the feasibility of the reliability testing device, and the degradation path of the predetermined degradation index is obtained.
Research on the Highly Accelerated Stress Screening (HASS) Test Process of Civil Aircraft Airborne Equipment
Authors: Lu Peng , Yang Xuerui
Published: February 2021

The reliability of the airborne equipment of civil aircraft is highly concerned by the aircraft Original Equipment Manufacture (OEM), airlines, passengers and airworthiness authorities, and is the key to ensuring the safety and punctual operation of the aircraft. The Highly Accelerated Stress Screening (HASS) test is one of the effective test methods to ensure that the product reaches the expected reliability level, and it has been widely used in aviation, high-speed rail, automobiles and other fields. Based on the characteristics of civil aircraft airborne equipment, combined with the universal method of HASS test, this paper investigates the application process of HASS test on airborne equipment, and gives the method for determining the test object of airborne equipment by HASS, and the test of HASS, the principles of test profile design, follow-up verification and troubleshooting methods. The research can be applied to the HASS test work of civil aircraft airborne equipment, and guide the development of HASS test, so as to effectively propose defective products in the manufacturing stage and improve the reliability of the installed airborne equipment.
Content Sharing Network based on IPFS and Blockchain
Authors: Xu Haimei , Cheng Yan , Li Zhengdong , You Chunyan
Published: February 2021

In this paper, we propose one content-sharing system InnerLight based on IPFS and BlockChain, which is a creation and public discussion platform about mental health. InnerLight put copies of articles from creators on IPFS to achieve distributed storage of contents and complete the first step of returning the data to creators. At the same time, it also encourages creators and readers to maintain the sustainable development of the system through blockchain-based cryptocurrency. In addition to IPFS and Blockchain, ranking algoithms contribute to make Innerlight to be a decentralized autonomous ecosystem.
Reliability Evaluation for Complex System Based on Bayesian Theory and Multi-Source Information Fusion
Authors: Song Zhaoli , Zhao Qian , Jia Xiang , Guo Bo
Published: February 2021

For large complex systems, it is of great importance to study effective approaches for reliability evaluation. In this paper, a system reliability evaluation method based on Bayesian theory and multi-source information fusion is proposed. Firstly, model the reliability of system network, including the establishment of system reliability block diagram and the determination of the system and components’ life distributions. Then, the posterior distributions and posterior moments of component reliability are determined. With the posterior moments, the failure information of components can be converted to the prior moment of the system reliability according to the system structure, and the system prior distribution can be obtained. Finally, combined with the system-level field data, the posterior distribution of system reliability can be obtained on the basis of Bayesian theory, and be utilized to evaluate the reliability of system. To fill out the shortage of field data, the proposed method in this paper can make full use of various quantitative and qualitative prior information with high accuracy.
An improved deep convolutional neural network with multiscale convolution kernels for fault diagnosis of rolling bearing
Authors: Fu Liangcheng , Zhang Li , Tao Junyong
Published: February 2021

With the help of multiple layers of nonlinear mapping capabilities, deep neural network models can adaptively extract fault features and diagnose faults, which improve the efficiency and accuracy of fault diagnosis. Based on Deep Convolutional Neural Networks with Wide First-layer Kernels (WDCNN), this paper proposes an improved model named Deep Convolutional Neural Networks with Multiscale First-layer Convolution Kernels (MDCNN). The proposed method uses 1D convolution kernels of different sizes to extract multiscale features from original vibration signals. Afterwards, to achieve feature fusion, different feature maps are reduced to the same size through adaptive convolution operations. Finally, through the learning of the multi-layer network, intelligent fault diagnosis from the signal to the health state is realized. A test based on CWRU dataset is performed to verify the accuracy of the proposed method for rolling bearing fault diagnosis. Results indicate that MDCNN shows higher performance than WDCNN.
Reliability analysis of discrete multi-state systems based on survival signature
Authors: Liang H , Mi J , Bai L , Cheng Y
Published: February 2021

System signature has been widely utilized to facilitate reliability assessment of coherent systems and networks consisting of a single type of components, which enables us to separate aspects of components’ failure time and system structure. Recently, survival signature fulfils the similar work, extended to the implementation of systems with multiple types of components. However, when the system has several states, the relevant work is limited to complete the reliability assessment by the survival signature. This paper proposed a novel pattern of survival signature for the multi-state system with multiple types of components and the presented approach is executed to demonstrate the validity via a numerical case with 2-type and 3-state components.
Structural dynamic reliability estimation with advanced extremum Kriging method
Authors: Zhao Y J , Lu C , Li H , Liu H T , Fei C W
Published: February 2021

To enhance the computational performance of the structural dynamic reliability estimation, advanced extremum Kriging method (AEKM) is proposed fusing Kriging surrogate model, multi-population genetic algorithm and response surface method-based extremum thought (ERSM) in this paper. The applicability of the AEKM is verified via the blisk radial deformation dynamic reliability analysis of an aeroengine high-pressure compressor. The results show that the reliability level of the blisk is 0.9956 as the allowable value of radial running deformation 1.75×10−3 m. Moreover, the developed AEKM is superior to other three surrogate models, including ERSM, K-ERSM and IK-ERSM, in terms of computing precision and analytical efficiency. Besides, the analytical precision of the developed method is basically consistent with the direct simulation, and the analytical time is obviously superior to the direct simulation. Therefore, the AEKM is illustrated to be an effective way for structural dynamic reliability analysis, which enriches complex structural reliability theory.
Instantaneous Availability of Multi-component System under the Constraint of Spare Parts
Authors: Wang Yun , Hu Pengwei , Jin Baidong , Cheng Hailong , Liu Yuhan
Published: February 2021

The availability of equipment is one of the most important indicators to measure support effectiveness of system, and spare parts supply is one of the key support resources, so it is necessary to consider the constraint of spare parts in the study of availability. As the evaluation of steady availability cannot meet the requirement of support effectiveness timely and accurately and the previous models of instantaneous availability are usually applicable to one-unit system. To solve the above problem, firstly, the whole process is divided into two sub-processes, i.e., the replace and repair process of fault system and the maintenance and turnover process of failure parts, then the influence between the two sub-processes is analysed. Secondly, a model that can compute the instantaneous availability of multi-component series system with spare parts is given. Finally, a numerical example is used to demonstrate the applicability and the performance of the proposed method.
Temperature characteristics of SOC estimation for traction battery system
Authors: Li D , Zhimao M , Mingsheng C
Published: February 2021

In order to determine the effect of temperature on the SOC estimation accuracy of the battery system, the electrical performance of the battery system was studied by charge/discharge and environmental testing equipment. When SOC is equal to or greater than 80%, the result shows larger error between the actual SOC of battery system and the recorded SOC of BMS system, which are 3.81% and 4.43% at -10 °C and 0 °C respectively, and the error is 2.41% at 25 C. The error between the actual SOC of battery system and the recorded SOC of BMS system tend to decrease firstly and then increase as the temperature increased, and the error is 0.31% at 25 C. In conclusion, temperature has a significant impact on the SOC estimation of battery system, the actual SOC of battery system shows a trend of rapid increase and followed by a rise slowly, while the recorded SOC of BMS system shows a trend of continuous increase, resulting in the error between the actual SOC and the recorded SOC. Besides, the minimum error of SOC estimation appears at 25 C.
Semi-supervised Fault Diagnosis Model Based on Improved Fuzzy C-means Clustering and Convolutional Neural Network
Authors: Wang Yumin , Han Minghong , Wu Yaman
Published: February 2021

The number of unlabeled data is much more than labeled data. There are some challenges in using existing complex data for fault diagnosis. Therefore, we proposed a semi-supervised fault diagnosis algorithm based on improved fuzzy C-means algorithm (IFCM) and Convolutional Neural Network (CNN). Firstly, the fault original signal is extracted by variational mode decomposition (VMD) and the singular value decomposition (SVD) to extract the fault feature vector. Secondly, IFCM is used to obtain the membership degree of the data to all categories, which integrates the labeled data into the cluster center of fuzzy C-means (FCM) to obtain better clustering results. The label of labeled data will spread to unlabeled data in the same category. Thirdly, data with a membership degree greater than the value of 0.9 will be selected as the core data set. Finally, the original signal and labels of core data set will be input into CNN for fault diagnosis. The result shows that the fault recognition rate of IFCM-CNN reaches 95%. The fault diagnosis effect is significantly better than other algorithms.
Modeling of UAV Integrated Logistics Support Process via an Agent-based Method
Authors: Zhang Q M , Hai X S
Published: February 2021

An agent-based integrated logistics support simulation and evaluation model for unmanned aerial vehicle (UAV) systems is proposed to meet the requirements of UAV system integrated support during mission execution. First, according to the typical mission execution process of a UAV system, the basic process of its use support and maintenance support is analyzed in depth. Second, considering the characteristics of multi-element function behavior, state transition and environmental change, the interaction relationship between agents is given, and then, a multi-agent model is established. Third, combined with the task execution process, a model evaluation algorithm based on the Monte Carlo method is proposed. Finally, the typical mission mode of a UAV system is selected to verify the model by taking the mission success rate and mission reliability as examples. The results show that the proposed model has enough flexibility and convergence speed and can support the analysis and evaluation of the UAV system integrated support process.
A preliminary mapping network model for unsafe acts in maritime accidents
Authors: Fu Shanshan , Zhuang Hui , Zhang Changjiang , Xi Yongtao
Published: February 2021

Unsafe acts are a critical issue causing maritime accidents. In order to explore the correlations between the crew’s unsafe acts and the induced maritime accidents, this paper proposes a preliminary mapping network model. Its first part is a hierarchical model, making crews’ unsafe acts as the top layer, skill-based failures, rule- and knowledge-based mistakes and violations acts as criteria, and basic unsafe acts (BUA) as the bottom layer. Therein, the BUAs are identified from 413 marine accident/incident investigation reports and 91 crews’ questionnaires. The second part is composed of several maritime accident types. The connection links between these two parts are aiming to reveal the correlations between each BUA and the specific maritime accident type. The proposed mapping network model can not only support unsafe acts analysis for one and multiple maritime accidents but also present the common BUAs for safety management.