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Advanced Machine Learning Methods for Prediction of Blast-Induced Flyrock Using Hybrid SVR Methods

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 1595-1617页

作者： Ji Zhou Yijun Lu Qiong Tian Haichuan Liu Mahdi Hasanipanah Jiandong Huang College of Civil and Environmental Engineering Hunan University of Science and EngineeringYongzhou425006China Hunan Provincial Key Laboratory of Intelligent Protection and Utilization Technology in Masonry Artifacts Hunan University of Science and EngineeringYongzhou425006China School of Civil Engineering Guangzhou UniversityGuangzhou510006China Institute of Research and Development Duy Tan UniversityDa Nang550000Vietnam School of Engineering&Technology Duy Tan UniversityDa Nang550000Vietnam

Blasting in surface mines aims to fragment rock masses to a proper size.However,flyrock is an undesirable effect of blasting that can result in human injuries.In this study,support vector regression(SVR)is combined with four algorithms:gravitational search algorithm(GSA),biogeography-based optimization(BBO),ant colony optimization(ACO),and whale optimization algorithm(WOA)for predicting flyrock in two surface mines in Iran.Additionally,three other methods,including artificial neural network(ANN),kernel extreme learning machine(KELM),and general regression neural network(GRNN),are employed,and their performances are compared to those of four hybrid SVR models.After modeling,the measured and predicted flyrock values are validated with some performance indices,such as root mean squared error(RMSE).The results revealed that the SVR-WOA model has the most optimal accuracy,with an RMSE of 7.218,while the RMSEs of the KELM,GRNN,SVR-GSA,ANN,SVR-BBO,and SVR-ACO models are 10.668,10.867,15.305,15.661,16.239,and 18.228,respectively.Therefore,combining WOA and SVR can be a valuable tool for accurately predicting flyrock distance in surface mines.

关键词： Flyrock induced by blasting optimization algorithms SVR GRNN

Halanay-type inequality with delayed impulses and its applications

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Science China(Information Sciences) 2019年第9期62卷 158-167页

作者： Yaqi WANG Jianquan lu yijun LOU The Jiangsu Provincial Key Laboratory of Networked Collective Intelligence School of MathematicsSoutheast University Department of Applied Mathematics The Hong Kong Polytechnic University

In this study, some properties of a novel Halanay-type inequality that simultaneously contains impulses and delayed impulses are investigated. Two concepts with respect to average impulsive gain are proposed to describe hybrid impulsive strength and hybrid delayed impulsive strength. Then, using the obtained results, two stability criteria are derived for the linear systems with impulses and delayed impulses.It is found that the stability of impulsive systems is robust with respect to delayed impulses of which the magnitude strength is relatively small. Whereas, if the impulse strength is small, the time-delayed impulses can also promote the stability of unstable systems. Two numerical examples are employed to illustrate the efficiency of our results.

关键词： Halanay-type inequality hybrid impulses average impulsive gain delayed impulses linear impulsive systems

GMSK iterative carrier recovery for AIS burst-mode

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The Journal of China Universities of Posts and Telecommunications 2017年第3期24卷 1-6页

作者： lu Xiwen luo yijun Li Jie School of Electronic Information Wuhan University Xi'an Institute of Space Radio Technology

In this paper, an iterative carrier recovery algorithm of Gaussian filtered minimum shift keying （GMSK） in burst-mode was designed. The data utilization rate and precision of the traditional demodulation method for recovering carrier signal in burst data packet with limited-length is poor. In order to solve this problem, this paper proposed an iterative carrier recovery algorithm. This algorithm can improve the estimated precision of carrier recovery and data utilization rate of burst data packet in a large extent by performing multiple forward and backward iterations. And the algorithm can be implemented in Simulink environment. As the communication mode of automatic identification system （AIS） is abrupt, the algorithm is especially suitable for satellite-based AIS.

关键词： kGMSK iteration cartier recovery AIS burst signal

The effect of SiO_2 particle size on iron based F–T synthesis catalysts

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Chinese Journal of Chemical Engineering 2016年第7期24卷 937-943页

作者： Xiuying Guo Yijun Lu Peng Wu Kui Zhang Qinghua Liu Mingsheng luo National Institute of Clean and Low Carbon Energy Beijing 102209 China

The effect of particle size of silica, as catalyst binder, on the chemical and mechanical properties of iron based FT catalyst was studied in this work. The samples were characterized using XRD, BET, TEM, FT-IR, and H2-TPR, respectively. The attrition resistance and the FT activity were tested. Si-8–Si-15 catalysts prepared with 8–15 nm silica sol show good attrition resistance(attrition loss b 4%), especially Si-13 with an attrition loss of 1.89%. Hematite appeared in XRD patterns when silica sol above 15 nm is used. TEM micrographs show that no obvious Si O_2 particles appear when silica sol particle with size less than 8 nm was used, but Si O_2 particles coated with small ferrihydrite particles appear when silica sol above 8 nm was used. Si–O–Si vibration peak in FT-IR spectra increases with increasing silica sol size. Samples prepared with silica sol show good stability of FT reactions, and the average molecular weight of FT products increases with the increase of Si O_2 particle.

关键词： SiO2颗粒铁基催化剂颗粒尺寸合成催化剂二氧化硅粒子纳米硅溶胶催化剂制备 XRD图谱

The influence of the corporate social responsibility disclosures on consumer brand attitudes under the impact of CO VID-19

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Frontiers of Business Research in China 2020年第4期14卷 426-447页

作者： Fengjun Liu lu Meng yijun Zhao Shen Duan Business School Renmin University of ChinaBeijing 100872China

This study focuses on the use of we-media by small-and medium-sized enterprises(SMEs)to disclose internal corporate social responsibility(ICSR)under the impact of the 2019 novel coronavirus disease(COVID-19).Study 1 interprets the catalyst effect of COVID-19 on the externalization of SMEs'ICSR.The fuzzy grading evaluation method is initially verified.Under the impact of COVID-19,SMEs fulfilling their ICSR can enhance consumer brand attitudes.Study 2 uses a structural equation model and empirical analysis of 946 effective samples and finds that consumers perceive the self-sacrifice of corporations during the coronavirus disease period.SMEs can fulfill their ICSR to enhance the internal explanation mechanism of consumer brand attitudes and the moderating role of enterprise losses.

关键词： 2019 novel coronavirus disease(COVID-19) Small-and medium-sized enterprises(SMEs) Internal corporate social responsibility(ICSR) Enterprise social responsibility disclosures Consumer brand attitudes

Recent Advances in Atomic-scale Storage Mechanism Studies of Two-dimensional Nanomaterials for Rechargeable Batteries Beyond Li-ion

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Chemical Research in Chinese Universities 2020年第4期36卷 560-583页

作者： PAN lu DONG Jinyang YI Ding YANG yijun WANG Xi Department of Physics School of ScienceBeijing Jiaotong UniversityBeijing 100044P.R.China Chemistry ami Chemical Engineering Guangdong Laboratory Shantou 515031P.R.China Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081P.R.China

Developing new types of rechargeable batteries with high energy densities and low cost have received in creasing attentions,aiming to reduce the dependence on high-priced lithium.Bevond Li-ion batteries,the potential alternatives including Na-ion batteries,Li-S batteries and Li-air batteries have been investigated recently,which are required to be viable for commercial applications.From this point of view,to understand the electrochemical reaction mechanisms and kinetics of these batteries has become the key challenge to make breakthroughs in the field of new energy storage.In this review,we present a critical overview of the two dimensional nanomaterials-based batteries(except Li-ion-based batteries)that could meet such demonds.To develop new energy storage devices with more promising performances,the microstructure evolution and atomic scale storage mechanism of these batteries are comprehensively summarized.In addition,the major challenges and opportunities of advanced characterization techniques are finally discussed.We do hope that this review will give the readers a clear and profound understanding of the electrochemical reaction mechanisms and kinetics of the as-discussed batteries.thus effectively contributing to the smart design of future-generation energy storage devices.

关键词： Two dimensional(2D)nanomaterial Batteries beyond Li ion In sinu technique Atomic-level Storage mechanism and kinetics

Dissolvable temporary barrier:a novel paradigm for flexible hydrogel patterning in organ-on-a-chip models

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Bio-Design and Manufacturing 2024年第2期7卷 153-166页

作者： Ding Wang Qinyu Li Chenyang Zhou Zhangjie Li Kangyi lu yijun Liu Lian Xuan Xiaolin Wang Department of Micro/Nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Ophthalmology LKS Faculty of MedicineThe University of Hong KongHong Kong 999077China Institute of Medical Robotics Shanghai Jiao Tong UniversityShanghai 200240China National Key Laboratory of Advanced Micro and Nano Manufacture Technology Shanghai Jiao Tong UniversityShanghai 200240China National Center for Translational Medicine(Shanghai)SHU Branch Shanghai UniversityShanghai 200444China

A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.

关键词： Dissolvable temporary barrier Hydrogel patterning Microfluidics Organ-on-a-chip Vascularization

Recent observations and research progresses of terrestrial gamma-ray flashes during thunderstorms

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Science China Earth Sciences 2023年第3期66卷 435-455页

作者： Fanchao LYU yijun ZHANG Gaopeng lu Baoyou ZHU Hongbo ZHANG Wei XU Shaolin XIONG Weitao LYU Key Laboratory of Transportation Meteorology of China Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210041China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Atmospheric Sciences Fudan UniversityShanghai 200441China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100081China Electronic Information School Wuhan UniversityWuhan 430072China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100081China

Terrestrial gamma-ray flashes(TGFs)are high-energy emissions in thunderstorms that were discovered first by satellite-based and then by ground-based gamma-ray detectors with photon energy up to tens of Me V.TGFs are a natural highenergy phenomenon associated with lightning discharges that frequently occur during thunderstorms.However,their production mechanisms and associated processes are still unclear.TGF studies have already been a research spotlight in the atmospheric electricity and high-energy atmosphere research areas.In this paper,we review recent research progresses on TGF studies in the past decade,including TGF detection,the relationship between TGFs and lightning processes,and thunderstorm activities.Several unsolved important scientific questions are discussed.Results suggest that upward TGFs observed by satellite-based detectors are closely connected with the development of in-cloud upward negative leaders.They are usually generated in milliseconds of the initiation of upward negative leaders and may produce a kind of distinct radio emissions because of the generation and propagation of huge amounts of high-energy electrons.By contrast,its counterpart,i.e.,downward TGFs observed by ground-based gamma-ray detectors,is associated with different types of lightning processes,such as downward negative or upward positive leaders,the initial continuing current stage of rocket-triggered lightning flashes return stroke processes.Because of limited observations,how these downward TGFs are generated is still unclear.Benefiting from the development of state-of-the-art instruments with high temporal and spatial resolutions,new insights into the processes and mechanisms of TGFs will be achieved with coordinated observations from satellite-based and ground-based measurements.

关键词： Terrestrial gamma-ray flashes(TGFs) Lightning Thunderstorm High-energy emissions Radio emission detection

TOX deficiency facilitates the differentiation of IL-17A-producingγδT cells to drive autoimmune hepatitis

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Cellular & Molecular Immunology 2022年第10期19卷 1102-1116页

作者： Qifeng He Yijun Lu Wenfang Tian Runqiu Jiang Weiwei Yu Yong Liu Meiling Sun Fei Wang Haitian Zhang Ning Wu Zhongjun Dong Beicheng Sun Department of Hepatobiliary Surgery Affiliated Drum Tower HospitalMedical School of Nanjing UniversityNanjingChina Department of Hepatobiliary Surgery The First Affiliated Hospital of Anhui Medical UniversityHefeiChina

The specification of theαβ/γδlineage and the maturation of medullary thymic epithelial cells(mTECs)coordinate central tolerance to self-antigens.However,the mechanisms underlying this biological process remain poorly clarified.Here,we report that dual-stage loss of TOX in thymocytes hierarchically impaired mTEC maturation,promoted thymic IL-17A-producingγδT-cell(Tγδ17)lineage commitment,and led to the development of fatal autoimmune hepatitis(AIH)via different mechanisms.Transfer ofγδT cells from TOX-deficient mice reproduced AIH.TOX interacted with and stabilized the TCF1 protein to maintain the balance ofγδT-cell development in thymic progenitors,and overexpression of TCF1 normalizedαβ/γδlineage specification and activation.In addition,TOX expression was downregulated inγδT cells from AIH patients and was inversely correlated with the AIH diagnostic score.Our findings suggest multifaceted roles of TOX in autoimmune control involving mTEC and Tγδ17 development and provide a potential diagnostic marker for AIH.

关键词： Autoimmune hepatitis γδT cell IL-17A Immune tolerance TOX