检索结果-南通市图书馆

Optimization of fixed aviation support resource station configuration for aircraft carrier based on aircraft dispatch mission scheduling

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2023年第2期36卷 127-138页

作者： Yujie LIU Wei HAN Xichao SU Rongwei CUI Aeronautical Foundation College Naval Aviation UniversityYantai 264001China Aeronautical Operations College Naval Aviation UniversityYantai 264001China

Before the dispatch of the carrier-based aircraft,a series of pre-flight preparation operations need to be completed on the flight deck.Flight deck fixed aviation support resource station configuration has an important impact on operation efficiency and sortie rate.However,the resource station configuration is determined during the aircraft carrier design phase and is rarely modified as required,which may not be suitable for some pre-flight preparation missions.In order to solve the above defects,the joint optimization of flight deck resource station configuration and aircraft carrier pre-flight preparation scheduling is studied in this paper,which is formulated as a two-tier optimization decision-making framework.An improved variable neighborhood search algorithm with four original neighborhood structures is presented.Dispatch mission experiment and algorithm performance comparison experiment are carried out in the computational experiment section.The correlation between the pre-flight preparation time(makespan)and flight deck cabin occupancy percentage is given,and advantages of the proposed algorithm in solving the mathematical model are verified.

关键词： Carrier-based aircraft Multi-objective optimization Resource configuration Scheduling Variable neighborhood search

Persymmetric adaptive detection of range-spread targets in subspace interference plus Gaussian clutter

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2023年第5期66卷 271-282页

作者： Tao JIAN Jia HE Yu LIU You HE Congan XU Zikeng XIE Research Institute of Information Fusion Naval Aviation University

In this paper, we consider the adaptive detection problem of range-spread targets embedded in subspace interference plus structured Gaussian clutter. The target signal and interference are assumed to lie in two linearly independent subspaces with unknown coordinates. The clutter component is modeled as a complex Gaussian vector with an unknown persymmetric covariance matrix. We leverage the persymmetric structure to design a two-step detector according to the Rao test criterion. The theoretical results show that the proposed detector possesses the constant false alarm rate property with respect to the clutter covariance matrix. Furthermore, the numerical results show that the proposed detector exhibits better detection performance than the existing unstructured subspace detectors, particularly under a limited training data size. In addition, the proposed detector outperforms the existing persymmetric subspace detectors.

关键词： adaptive detection persymmetry structured interference constant false alarm rate Rao test

An Adaptive Interactive Multiple-Model Algorithm Based on End-to-End Learning

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2023年第5期32卷 1120-1132页

作者： ZHU Hongfeng XIONG Wei CUI Yaqi Institute of Information Fusion Naval Aviation University

The interactive multiple-model(IMM) is a popular choice for target tracking. However, to design transition probability matrices(TPMs) for IMMs is a considerable challenge with less prior knowledge, and the TPM is one of the fundamental factors influencing IMM performance. IMMs with inaccurate TPMs can make it difficult to monitor target maneuvers and bring poor tracking results. To address this challenge, we propose an adaptive IMM algorithm based on end-to-end learning. In our method, the neural network is utilized to estimate TPMs in real-time based on partial parameters of IMM in each time step, resulting in a generalized recurrent neural network. Through end-to-end learning in the tracking task, the dataset cost of the proposed algorithm is smaller and the generalizability is stronger. Simulation and automatic dependent surveillance-broadcast tracking experiment results show that the proposed algorithm has better tracking accuracy and robustness with less prior knowledge.

关键词： Maneuvering target tracking Neural networks End-to-end learning Interactive multiple-model Model transition probability matrix

Quasi-LFM radar waveform recognition based on fractional Fourier transform and time-frequency analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2021年第5期32卷 1130-1142页

作者： XIE Cunxiang ZHANG Limin ZHONG Zhaogen Department of Information Fusion Naval Aviation UniversityYantai 264001China School of aviation Basis Naval Aviation UniversityYantai 264001China

Recent advances in electronics have increased the complexity of radar signal modulation.The quasi-linear frequency modulation(quasi-LFM)radar waveforms(LFM,Frank code,P1−P4 code)have similar time-frequency distributions,and it is difficult to identify such signals using traditional time-frequency analysis methods.To solve this problem,this paper proposes an algorithm for automatic recognition of quasi-LFM radar waveforms based on fractional Fourier transform and time-frequency analysis.First of all,fractional Fourier transform and the Wigner-Ville distribution(WVD)are used to determine the number of main ridgelines and the tilt angle of the target component in WVD.Next,the standard deviation of the target component's width in the signal's WVD is calculated.Finally,an assembled classifier using neural network is built to recognize different waveforms by automatically combining the three features.Simulation results show that the overall recognition rate of the proposed algorithm reaches 94.17%under 0 dB.When the training data set and the test data set are mixed with noise,the recognition rate reaches 89.93%.The best recognition accuracy is achieved when the size of the training set is taken as 400.The algorithm complexity can meet the requirements of real-time recognition.

关键词： quasi-linear frequency modulation(quasi-LFM)radar waveform time-frequency distribution fractional Fourier transform(FrFT) assembled classifier

Initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第1期35卷 277-289页

作者： Yangguang ZHANG Yueliang CHEN Yong ZHANG Guixue BIAN Chenguang WANG Andong WANG Naval Aviation University Qingdao Campus Qingdao 266041China

The initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments(pH=3.5)are studied by Scanning Electron Microscope(SEM),optical microscope,Fourier Transform Infrared Spectroscopy(FT-IR),X-Ray Diffraction(XRD),potentiodynamic polarization,Electrochemical Impedance Spectroscopy(EIS),and Scanning Kelvin Probe(SKP).The results show that pitting corrosion occurs at the initial corrosion stage,and the potential difference between the second phase particles is the main cause of pitting.Pitting pits on different locations gradually expand and coalesce with the proceeding of corrosion.The main components of corrosion products are Al_(2)O_(3),Al(OH)_(3),and AlCl_(3),and the generation rate of the corrosion product layer under the salt spray environment is larger than that under acid immersion environment.Under both environments,the Volta potential distribution first disperses and then concentrates,while the charge transfer resistance first decreases and then increases with the corrosion time.The Volta potential gradually shifts in a positive direction,indicating that corrosion products have an inhibitory effect on corrosion.After the same corrosion time,the corrosion product layer resistance and the expectation of the Volta potential of the salt spray sample are higher than those of the immersion sample.Comparatively,the corrosion current density for the salt spray sample is significantly lower than the immersion sample,which indicates that the thicker the corrosion product layer,the stronger the inhibition of corrosion reaction.

关键词： 7B04 aluminum alloy Acid salt spray Corrosion mechanism Corrosion products Electrochemistry Scanning Kelvin probe

Combination for Conflicting Interval-Valued Belief Structures with CSUI-DST Method

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2022年第5期31卷 980-990页

作者： LI Shuangming GUAN Xin YI Xiao SUN Guidong Naval Aviation University Unit 92941 of PLA Unit 32801 of PLA

Since the basic probability of an intervalvalued belief structure(IBS) is assigned as interval number, its combination becomes difficult. Especially, when dealing with highly conflicting IBSs, most of the existing combination methods may cause counter-intuitive results,which can bring extra heavy computational burden due to nonlinear optimization model, and lose the good property of associativity and commutativity in Dempster-Shafer theory(DST). To address these problems, a novel conflicting IBSs combination method named CSUI(conflict,similarity, uncertainty, intuitionistic fuzzy sets)-DST method is proposed by introducing a similarity measurement to measure the degree of conflict among IBSs, and an uncertainty measurement to measure the degree of discord, non-specificity and fuzziness of IBSs. Considering these two measures at the same time, the weight of each IBS is determined according to the modified reliability degree. From the perspective of intuitionistic fuzzy sets, we propose the weighted average IBSs combination rule by the addition and number multiplication operators. The effectiveness and rationality of this combination method are validated with two numerical examples and its application in target recognition.

关键词： Conflicting IBSs Similarity and uncertainty measure Addition and number multiplication operators Weight

FOLMS-AMDCNet:an automatic recognition scheme for multiple-antenna OFDM systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

系统工程与电子技术：英文版 2023年第2期34卷 307-323页

作者： ZHANG Yuyuan YAN Wenjun ZHANG Limin LING Qing Academy of Aeronautical Operations Service Naval Aviation UniversityYantai 264001China

The existing recognition algorithms of space-time block code(STBC)for multi-antenna(MA)orthogonal frequencydivision multiplexing(OFDM)systems use feature extraction and hypothesis testing to identify the signal types in a complex communication environment.However,owing to the restrictions on the prior information and channel conditions,these existing algorithms cannot perform well under strong interference and noncooperative communication conditions.To overcome these defects,this study introduces deep learning into the STBCOFDM signal recognition field and proposes a recognition method based on the fourth-order lag moment spectrum(FOLMS)and attention-guided multi-scale dilated convolution network(AMDCNet).The fourth-order lag moment vectors of the received signals are calculated,and vectors are stitched to form two-dimensional FOLMS,which is used as the input of the deep learning-based model.Then,the multi-scale dilated convolution is used to extract the details of images at different scales,and a convolutional block attention module(CBAM)is introduced to construct the attention-guided multi-scale dilated convolution module(AMDCM)to make the network be more focused on the target area and obtian the multi-scale guided features.Finally,the concatenate fusion,residual block and fully-connected layers are applied to acquire the STBC-OFDM signal types.Simulation experiments show that the average recognition probability of the proposed method at−12 dB is higher than 98%.Compared with the existing algorithms,the recognition performance of the proposed method is significantly improved and has good adaptability to environments with strong disturbances.In addition,the proposed deep learning-based model can directly identify the pre-processed FOLMS samples without a priori information on channel and noise,which is more suitable for non-cooperative communication systems than the existing algorithms.

关键词： blind signal identification(BSI) space-time block code(STBC) orthogonal frequency-division multiplexing(OFDM) deep learning fourth-order lag moment spectrum(FOLMS)

Threat evaluation method of warships formation air defense based on AR(p)-DITOPSIS

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2019年第2期30卷 297-307页

作者： SUN Haiwen XIE Xiaofang Coastal Defense College Naval Aviation University

For the target threat evaluation of warships formation air defense, the sample data are frequently insufficient and even incomplete. The existing evaluation methods rely too much on expertise and are difficult to carry out for the dynamic evaluation on time series. In order to solve these problems, a threat evaluation method based on the AR(p)(auto regressive(AR))-dynamic improved technique for order preference by similarity to ideal solution(DITOPSIS) method is proposed. The AR(p) model is adopted to predict the missing data on the time series. Then, the entropy weight method is applied to solve each index weight at the objective point. Kullback-Leibler divergence(KLD) is used to improve the traditional TOPSIS, and to carry out the target threat evaluation. The Poisson distribution is used to assign the weight value.Simulation results show that the improved AR(p)-DITOPSIS threat evaluation method can synthetically take into account the target threat degree in time series and is more suitable for the threat evaluation under the condition of missing the target data than the traditional TOPSIS method.

关键词： AR(p) model Kullback-Leibler divergence (KLD) dynamic improved technique for order preference by similarity to ideal solution (DITOPSIS) time series threat evaluation

Obstacle avoidance method of three-dimensional obstacle spherical cap

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2018年第5期29卷 1058-1068页

作者： YANG Xiuxia ZHANG Yi ZHOU Weiwei Naval Aviation University Yantai 264001China

Focusing on obstacle avoidance in three-dimensional space for unmanned aerial vehicle(UAV), the direct obstacle avoidance method in dynamic space based on three-dimensional velocity obstacle spherical cap is proposed, which quantifies the influence of threatening obstacles through velocity obstacle spherical cap parameters. In addition, the obstacle avoidance schemes of any point on the critical curve during the multi-obstacles avoidance are given. Through prediction, the insertion point for the obstacle avoidance can be obtained and the flight path can be replanned. Taking the Pythagorean Hodograph(PH) curve trajectory re-planning as an example, the three-dimensional direct obstacle avoidance method in dynamic space is tested. Simulation results show that the proposed method can realize the online obstacle avoidance trajectory re-planning, which increases the flexibility of obstacle avoidance greatly.

关键词： three-dimensional direct space obstacle avoidance velocity obstacle cone velocity obstacle spherical cap