Journal of Northeastern University(Natural Science)

Dissipative Fuzzy Control for Singular Markovian Jump Systems with Generally Uncertain Transition Rates

ZHOU Juan， BAI Li-ping

2023, 44 (9): 1217-1226. DOI: 10.12068/j.issn.1005-3026.2023.09.001

Abstract ( 791 )

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The problem of dissipative fuzzy control for singular Markovian jump systems is studied with generally uncertain transition rates. Firstly， a new Lyapunov-Krasovskii functional is established to develop the new bounded real lemma (BRL) which guarantee the system to be stochastically admissible with given dissipative performance α. Delay decomposition approach and new inequality to deal with functional are used， which can reduce the conservatism to a certain extent. Secondly， based on these ingredients， the explicit expression of the desired controller is obtained by solving a set of strict linear matrix inequalities (LMIs). In the design process of the controller， the generally uncertain transition rates are divided into two cases， and then obtain the LMIs in two different cases. Finally， some numerical examples reflect the less conservatism and effectiveness of the method in this article.

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Improved Object Tracking Algorithm Based on SiamBAN Tracker

ZHENG Yan， ZHAO Jia-xu， BIAN Jie

2023, 44 (9): 1227-1233. DOI: 10.12068/j.issn.1005-3026.2023.09.002

Abstract ( 560 )

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The siamese network series tracker utilizes the similarity matching method for object tracking， but tracking drift can occur when similar distractors are encountered， leading to tracking failure. To solve this problem， based on the research of SiamBAN tracker， an improved algorithm is proposed. Major improvements include the addition of a centerness branch during training to reduce bounding box scores far from the object center， the introduction of the Focal Loss function， and a new screening strategy during inference to differentiate the target from similar distractors. Compared with the original， the success plot and precision plot of the improved algorithm are increased by 2.1% and 3% respectively on the OTB100 test set， and the success plot is 2.1% higher than the original on the GOT10k test set.

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A Multi-factor Correlation Analysis Method for Typhoon Moving Track Based on NMI and HSIC0

QIAO Bai-you， HAO Yuan-qing， TANG Zhong， WANG Rui

2023, 44 (9): 1234-1244. DOI: 10.12068/j.issn.1005-3026.2023.09.003

Abstract ( 422 )

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The existing nonlinear correlation analysis methods have low accuracy and high computational cost， making them unsuitable for the correlation analysis of large-scale and high-dimensional typhoon track data.To solve this problem，the Hilbert-Schmidt independent criterion empirical estimation (HSIC0) is introduced into typhoon track correlation study for the first time， and a multi-factor correlation analysis method based on normalized mutual information (NMI) and HSIC0 is proposed. The method first uses NMI to filter out redundant factors with low correlation in typhoon data， and then uses XGBoost to eliminate invalid factors， thus reducing the subsequent computational costs.On this basis， a multi-factor correlation analysis method based on HSIC0 is used to analyze typhoon data， and a combination of factors affecting typhoon moving track with strong correlation is mined， thereby improving the prediction accuracy of typhoon moving track.A series of experimental results on real typhoon data sets show that the proposed method outperforms the correlation analysis methods such as NMI， Pearson correlation coefficient， and distance correlation coefficient in indicators such as MSE， MAE， R^○2.

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A Stacked Generalization Ensemble-based Hybrid LGBM-RF-XGB Model for Sintering Moisture Prediction

HUANG Chuan-qi， REN Yu-qian， WU Zhao-xia

2023, 44 (9): 1245-1250. DOI: 10.12068/j.issn.1005-3026.2023.09.004

Abstract ( 528 )

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In order to predict the moisture of the mixture， a modeling method based on stacked generalization ensemble is introduced， and a Robust Scaler-Rank Gauss (RS-RG) hybrid algorithm is proposed to process the data input to the stacking model， and then the LGBM-RF-XGB hybrid model is established for sintered mixture moisture prediction based on stacked generalization ensemble， which can predict the moisture value before sinter mixture mixing. The internal mechanism of the LGBM-RF-XGB overlay model consists of generating metadata from the LGBM and RF models to calculate the final prediction using the XGB model. The proposed stacking model was simulated in comparison with several reference models by combining the sintering site data. The results show that the accuracy and error of the proposed stacking model are better than those of the reference models used for comparison， which meets the sintering process requirements. The proposed algorithm can be used for advance prediction of sinter mix moisture in actual production and provides a theoretical basis for automatic control of water addition.

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A Text Summarization Model Guided by Key Information

LIN Zhou， ZHOU Qi-feng

2023, 44 (9): 1251-1258. DOI: 10.12068/j.issn.1005-3026.2023.09.005

Abstract ( 429 )

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Existing abstractive text summarization models lack attention to keyword information， which leads to the loss of key information in the input text. A keyword semantic information enhancement pointer-generator networks， named KSIE-PGN， is proposed. Firstly， the keyword selection model KSBERT is built to extract keywords. Secondly， a keyword-masked coverage mechanism based on the information of keywords is proposed. When using the coverage mechanism， the continuous attention to keywords in the decoding process is retained. Then， the KSIE-PGN model integrates keyword information in the decoding process including the keyword semantic vector and the keyword context vector. Therefore， the decoder can avoid losing the key information in the input text. The experimental results on the CNN/Daily Mail dataset show that the model can capture the key information in the input text well.

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Segmentation of COVID-19 CT Images Based on Dual Attention Mechanism

JIANG Yang， LIU Cheng， DING Qi-chuan， WANG Li

2023, 44 (9): 1259-1268. DOI: 10.12068/j.issn.1005-3026.2023.09.006

Abstract ( 607 )

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Rapid and accurate segmentation of COVID-19 lesions from CT images is an important step to realize computer-assisted diagnosis and treatment of COVID-19. Therefore， a CT image segmentation method of COVID-19 lesions based on dual-attention mechanism is proposed. Firstly， the attention gate module is introduced to enhance the focus on the focal region in space and reduce the influence of image brightness imbalance and low contrast on the segmentation accuracy. Secondly， the SE-Res module combined with residual element was introduced to enhance the channel of the lesion region， extract the fine structural features， and improve the segmentation performance of the network for the lesion shape change and ground glass boundary region. Experiments on the public datasets of COVID-19 show that the Dice， PPV and IoU achieved by the proposed method are 0.9088， 0.9152 and 0.8589， respectively， which are 0.75%， 0.11% and 0.65%higher than previous studies， respectively. The proposed method can improve the segmentation accuracy of the lesions with large shape changes and ground glass boundaries， and the overall performance is better than current mainstream models.

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Effect of w(Fe)/w(Ni) Ratio on Mo₂FeB₂ Based Cermet

LIU Jun-ru， ZHANG Guo-hua， ZHOU Guo-zhi

2023, 44 (9): 1269-1278. DOI: 10.12068/j.issn.1005-3026.2023.09.007

Abstract ( 498 )

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Mo₂FeB₂ based cermets with different w(Fe)/w(Ni)(10∶0， 7∶3， 5∶5， 3∶7) were prepared by the vacuum liquid phase sintering with MoB， Fe， Ni， and Cr powders as raw materials. The effects of w(Fe)/w(Ni) on the phase compositions， microstructures and mechanical properties of cermets were investigated. The results showed that the compositions of hard and binder phases of boride-based cermet with different w(Fe)/w(Ni) were different. When w(Fe)/w(Ni) of 3∶7， the hard phase was composed of Mo₂NiB₂ and Mo₂FeB₂; while in the cases of other w(Fe)/w(Ni)， the hard phase was Mo₂FeB₂. At 1350℃， the microstructure of cermets was uniform and the size of pore is minimized， with the increase of sintering temperature， the hard-phase particles aggregated and the microstructure was not homogeneous， which led to the decrease of mechanical properties. After sintering at 1350℃ for 2h， the hardness and bending strength of the obtained cermet(w(Fe)/w(Ni)=10∶0) reached the maximum， which were 82.1 HRA and 1498.7MPa respectively. Meanwhile， the analysis of fracture morphology revealed that a large number of dimples and rich tearing edges are closely related to the improvement of the bending strength of cermets.

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Effects of Manganese Source on Synthesis and Adsorption Properties of Lithium Ion Sieve

LI Feng-hua， LIU Xiao， LI Ying-nan， FAN Rui

2023, 44 (9): 1279-1284. DOI: 10.12068/j.issn.1005-3026.2023.09.008

Abstract ( 538 )

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Manganese lithium ion sieve is suitable for extracting lithium from salt lakes with high magnesium lithium ratio in China. MnO₂·0.5H₂O lithium ion sieve were synthesized from three different manganese sources: MnSO₄， MnOOH and Mn₃O₄. The products were characterized by X-ray diffraction (XRD)，scanning electron microscope (SEM)， special surface area analysis (the BET method)， and atomic absorption spectrometer (AAS).The experimental results show that the three manganese sources can synthesize relatively pure Li_1.6Mn_1.6O₄ ion sieve precursors. After acid pickling， the BET specific surface areas of the three lithium ion sieves have increased significantly compared with the precursors， with increments of 546.6%， 129.9% and 142.2% respectively. Among them， the ion sieve synthesized by MnSO₄ has the largest specific surface area， and the ion sieve synthesized by Mn₃O₄ has a special rod shape. The adsorption results showed that the lithium adsorption capacity of the ion sieve synthesized by MnSO₄ source was the highest. In the low lithium solution with a concentration of only 20mg/L， the lithium extraction capacity was 19mg/g.

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Factors Influencing Single Abrasive Material Removal for Robotic Abrasive Belt Grinding

GONG Ya-dong， ZHAO Xian-li， ZHANG Wei-jian， TANG Ben-jia

2023, 44 (9): 1285-1291. DOI: 10.12068/j.issn.1005-3026.2023.09.009

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In order to study the effect of single abrasive material removal in robotic belt grinding， a single-grit scratch experiment based on robotic belt grinding was conducted. The removal behavior of robotic abrasive belt grinding of high-temperature alloys was investigated， and the variation patterns of scratch length， removal depth and pile-up ratio with grinding speed and set grinding depth were analyzed. The experimental results showed that with the increase of grinding speed， the scratch length and removal depth generally tended to decrease， and became locally larger when the grinding speed reached 10.99m/s. The accumulation ratio showed an overall increasing trend， and locally decreased at 10.99m/s. With the increase of the set grinding depth， both the scratch length and the removal depth increased， but they didn’t increase linearly. On the whole， the pile-up ratio showed a trend of decreasing and then increasing. The results of this study may provide an important reference for the optimization of the robotic belt grinding process.

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Effects of Phase Change Materials on the Heat Transfer Rate of Thermal Energy Storage System

WUSIMAN Kuerbanjiang， DAI Xiao-ye， SHI Lin

2023, 44 (9): 1292-1298. DOI: 10.12068/j.issn.1005-3026.2023.09.010

Abstract ( 468 )

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Phase change materials (PCMs) are the core media in latent heat thermal energy storage system， and phase change temperature， thermal conductivity and energy storage density of PCMs are the three most critical factors for selecting PCMs. These effects of three key factors of PCMs on heat transfer rate of thermal energy storage system are analyzed by means of relative thermal resistance variation according to thermal resistance modeling， respectively. The results indicate that when the thermal conductivity of PCMs is increased to about 2 folds， the heat transfer improvement of the system is significantly effective. After increasing to 5 folds， the effect of increasing the thermal conductivity to enhance the heat transfer rate of the system is almost invalid. During the charging process， the lower of PCMs’ phase change temperature is， the higher heat transfer rate becomes， and it’s just on the contrary during the discharging process. The increase of energy storage density has no effect on the heat transfer rate of the system， but the time of heat charging/discharging power is extended by corresponding multiple.

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More Than 100 Million DOF Numerical Simulation Technique and Its Engineering Application

HOU Jun-xu， YANG Tian-hong， MA Kai， ZHAO Yong

2023, 44 (9): 1298-1308. DOI: 10.12068/j.issn.1005-3026.2023.09.011

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In order to solve the problems of low accuracy and abnormal error in numerical simulation method for stability analysis of large-scale rock mass engineering， a more than 100 million degree-of-freedom(DOF)numerical simulation technique was developed. Taking the surface rock movement engineering of open-pit and underground combined mining at Dahongshan iron mine as an example， this technique is elaborated in detail. Combining the simulated results with the fissure of ground surface range， a method of the fissure of ground surface range inversed by fuzzy surface subsidence value is proposed. Combined with the more than 100 million DOF numerical simulation technique， this method accurately estimates the development of the fissure of ground surface range. The absolute error of position is 1.59~4.71m with a span error rate of 1.141%， verifing the reliability of the method and improving accuracy compared to the commonly numerical simulation method of millions DOF. At the same time， the fissure of ground surface range is estimated after 5 years. With the mining of underground 300~720m level ore body five years later， although the waste rock filling of collapse pit can inhibit the deformation of surrounding rock， the surface movement and cracking range will still affect the open-pit， and it is estimated that the crack area will affect the range above 990m steps at least in the open-pit.

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Common Precursor Characteristics of Uniaxial Compression Failure of Rocks with Different Lithology

ZHAO Yong， GU Xu-sheng， WANG Shu-hong， GAO Yang

2023, 44 (9): 1309-1317. DOI: 10.12068/j.issn.1005-3026.2023.09.012

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The strata in coal mines are often distributed in layers with coexisting lithologies. The precursory indicators obtained from the study of the rock instability of a single lithology can often be challenging to apply in practical engineering. Therefore， it is important to explore the relationship between the fracture process of different lithologic rocks in a coal mine and acoustic emission(AE)parameters and establish various lithologic rock stability evaluation mechanisms based on AE parameters. In view of this， an acoustic emission monitoring system was used to measure three sequential types of lithology rocks(fine sandstone， sandy mudstone and siltstone)taken from coal seams. Through examining the correlation of AE parameters， five AE parameters with low correlation， such as energy， b-value， dominant frequency， apparent stress and apparent volume， are selected as the precursor indexes of the rock failure， and a stability evaluation system suitable for these three lithology rocks is established. The research results provide a basis for coal mine disaster early warning and prediction based on microseismic monitoring in practical engineering.

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Ecological Cost of Open-Pit Coal Mine in Semi-arid Ecological Fragile Area of Xinjiang

YE Lu-qing， XU Xiao-chuan， GU Xiao-wei， WANG Qing

2023, 44 (9): 1318-1327. DOI: 10.12068/j.issn.1005-3026.2023.09.013

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The open-pit coal resource mining has caused great environmental pressure to the semi-arid region of Xinjiang where the ecological environment is fragile. Therefore， it is particularly important to evaluate the ecological disturbance and calculate the ecological value loss caused by the resource mining under the specific environment. According to the characteristics of semi-arid ecologically fragile area and the ecosystem service function under special environment， the ecological cost of mine is divided into direct economic value loss， exogenous ecological value loss， environmental pollution control cost， ecological cost of energy consumption， and reclamation cost， and the ecological cost model of open-pit coal mine in a semi-arid ecologically fragile area is established. The research results are applied to a specific open-pit coal mine in the semi-arid ecologically fragile area of Xinjiang， and the ecological cost of the mine is 2.328 billion yuan， accounting for 94.90% of the net present value of the mine. It can be seen that the ecological disturbance and ecological cost caused by resource exploitation in the semi-arid ecologically fragile area are severe， and if the mine takes the ecological cost into account in the mine financial statistics， it may experience significant reduction in profit.

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Investigation on Along-Track Geoid Resolution Capabilities of HY-2 Based on Spectrum Analysis

ZHOU Run-sheng， ZHANG Sheng-jun， KONG Xiang-xue

2023, 44 (9): 1328-1336. DOI: 10.12068/j.issn.1005-3026.2023.09.014

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The series of HY-2 satellites have accumulated a large amount of data， and the improvement of the resolution of the along orbit geoid of altimetry data is closely related to the refinement of the ocean gravity field model. This paper utilizes self-spectrum analysis， cross spectrum analysis， and coherence function calculation to estimate along orbit geoid resolution of satellite altimetry data. Spatially similar trajectory sequences of HY-2B and SARAL/AltiKa， as well as HY-2C and Jason-2， were selected to carry out the experiment. The results show that the average resolution of HY-2C is 19.15km， slightly better than HY-2B and Jason-2， but slightly lower than the SARAL/AlitKa Ka-band altimetry data with higher pulse repetition frequency. In addition， the repeated period collinear processing can significantly improve the resolution of along-track geoid by effectively suppressing noise. Under the condition of 5， 10 and 20 periods collinear processing， the resolution of HY-2B along orbit is improved by 19.26%， 38.56% and 46.69%， respectively. Therefore， when HY-2A， CryoSat-2 and other altimetry missions provide the observation sequence of geodetic missions with multi-period and repeated observations， the necessary collinear processing will bring more efficient data fusion for the refinement of marine gravity field model.

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Damage Mode and Safety Distances of Precast Columns Under Vehicle Induced Explosions

ZHU Zhao， LI Yuan， HAN Yi-tao

2023, 44 (9): 1337-1348. DOI: 10.12068/j.issn.1005-3026.2023.09.015

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The objective of this study is to estimate the blasting performance and define the safety distances for precast segmental bridge columns(PSBC). The constitutive model of concrete and steel bars， the state equation of air and TNT， and the parameters of joints are validated firstly through the explosion tests of cast-in-place(CIP)column and precast columns. Based on the verified parameters， the blast response of PSBC with different connections was analyzed using Autodyn. The analytical results showed that similar punching shear failure at column base occurs when the distance is less than 2m. When the blasting distance exceeds 3m， limited slippage occurs in PSBC connected by unbonded tendons and grouted corrugated ducts. On the contrary， typical bending-shear failure is discovered and negligible slippage is observed in partial precast columns. Combined with damage distribution， acceleration history， and stress of steel bars， the collapse can be avoided when explosive distances exceed 3m.

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Inter-bank Distress Propagation and Identification of Systemic Impact and Vulnerability: Based on DebtRank Algorithm

ZHENG Hong， BAO Rui， HUANG Wei-qiang

2023, 44 (9): 1349-1359. DOI: 10.12068/j.issn.1005-3026.2023.09.016

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Based on the overall data of inter-bank assets and inter-bank liabilities of China’s commercial banks， the inter-bank borrowing-lending correlation network is inferred indirectly by the maximum entropy method， and the distress propagation process under a single shock or common shocks is investigated based on the DebtRank algorithm. The systemic impact and vulnerability of banks and their influencing factors are also investigated. The empirical results show that under certain circumstances， the negative results brought by bank distress are more severe than those brought by bank default. China’s commercial banks are not located in the area of “high vulnerability/strong impact”， indicating that China’s banking system is relatively safe. In terms of influencing factors， the average return on assets has a significant negative effect on banks’ systemic impact， while the loan reserve ratio， the tier-one leverage capital ratio and the inter-bank lending volume have significant positive effect on banks’ systemic impact. The tier-one leverage capital ratio and asset size have significant negative effect on the systemic vulnerability and the inter-bank lending volume has significant positive effect on the systemic vulnerability. The results not only help banks to understand their own situations， but also provide a basis for financial regulation.

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Evaluation of Passengers’ Walking Convenience for Airport Comprehensive Transportation Hub Based on Spatial Experience

BAO Dan-wen， CHEN Zhuo， ZHOU Jia-yi， YAO Xin-yu

2023, 44 (9): 1359-1368. DOI: 10.12068/j.issn.1005-3026.2023.09.017

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The method of evaluating passengers’ walking convenience is critical for guiding the planning， design and optimization of an airport’s comprehensive transportation hub. Firstly， the smoothness evaluation index was constructed to capture the spatial layout characteristics of transfer facilities and to develop the walking convenience evaluation index system based on speed and timeliness. The spatial comprehensibility factor was then added to quantify the impact of complicated spatial visibility on passengers’ walking behavior. An evaluation method of walking convenience was proposed based on spatial experience. Finally， the differences in the level of walking convenience of each transportation mode at Nanjing Lukou Airport(NKG)were analyzed. The results showed that the evaluation method is more objective and accurate than the traditional methods， and the lowest walking convenience is from the metro station to the check-in hall of T1. The optimization strategy can improve the overall walking convenience by 8.2%， which is proposed in three aspects including the setting of walking traffic facilities.

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