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| 1 | Match Point Solution for Robust Flutter Analysis in Constant-Mach Prediction显示文摘This paper presents a method for robust flutter computation which uses flight altitude as the perturbation variable in order to obtain a match point solution. The air density and sound speed of standard atmosphere model are approximated as the polynomial function of altitude, such that the flight altitude becomes the single perturbation variable that describes the aeroelastic system. The uncertainties of generalized stiffness and damping are considered and the uncertain aeroelastic system can be formulated as linear fractional transforma- tion (LFT) representation which is suitable for μ analysis framework. Finally, the match point solutions of robust flutter margins can be computed with structured singular value (SSV) theory. The robust flutter analysis method provided in this paper is suitable for con- stant-Mach flight flutter test and provides valuable reference for flight envelope expansion. | Yun Haiwei Han Jinglong | 2008 | Chinese Journal of Aeronautics2008，21，2： | 9 |
| 2 | Hypersonic flutter and flutter suppression system of a wind tunnel model显示文摘The aeroelastic behavior of a thin flat rudder model was numerically simulated and experimentally investigated in a hypersonic wind tunnel. In particular, a flutter suppression system taking advantage of collision within small gaps was proposed and a novel system for the flutter simulation of the whole nonlinear aeroelastic system including the flutter suppression system was developed. First, the critical flutter dynamic pressure of the rudder without the flutter suppression system was calculated with different methods. Then, the whole nonlinear aeroelastic system, including theflutter suppression system, was simulated to design the gap size. Finally, the flutter suppression system was experimentally validated in a hypersonic wind tunnel operating at Mach number 5. The typical phenomenon of Limit Cycle Oscillation(LCO) was observed, avoiding the structural failure of the model and the consistency between numerical and experimental results was demonstrated.The proposed suppression system can improve the design and reusability of test models of hypersonic flutter experiments. | Chuanwei XUAN Jinglong HAN Bing ZHANG Haiwei YUN Xiaomao CHEN | 2019 | Chinese Journal of Aeronautics2019，32，9： | 3 |
| 3 | Magnetic resonance imaging characteristics of postoperative intracranial dissemination of recurrent gliomas显示文摘Ten intracranial gliomas cases, that had postoperative intracranial dissemination, underwent magnetic resonance imaging (MRI) examinations, including T1 weighted imaging, fat-suppressed T1 weighted imaging, T2 weighted imaging and fluid attenuated inversion recovery (FLAIR). Results showed that tumor metastasis had occurred via the cerebrospinal fluid, the brain white matter fibers and the surgical access site alone. On the plain MRI scans, 1/7 cases were linearly thickened with isointensity and 5/7 cases exhibited nodular foci on T1 weighted imaging; the cerebral sulci and cisterns in 2/7 cases had become shallow and five cases had nodular foci on T2 weighted imaging. FLAIR imaging revealed that the cerebral sulci and cisterns in 2/7 cases had become shallow and that six cases had affected nodular foci. The contrast-enhanced MRI scans revealed linear thickening in seven cases, nodules in seven cases, similarities to 'mould-like' signs in six cases and hydrocephalus in six cases. These findings suggested that MRI with different sequences can diagnose glioma metastasis. | Linfeng Zheng Guixiang Zhang Jinglong Zhao Han Wang Kang'an Li Lin Zhang Xifu Wang Pengpeng Sun Yunsheng Hu | 2011 | Neural Regeneration Research2011，6，33： | 1 |
| 4 | Correction method of airfoil thickness effect in hinge moment calculation of a folding wing显示文摘The influences of airfoil thickness on the aerodynamic loading distribution and the hinge moments of folding wing aircraft are presented in this work.The traditional panel method shows deficiencies in the calculation of folding wing's hinge moments.Thus, a thickness correction strategy for the aerodynamic model with CFD results is proposed, and an aeroelastic flight simulation platform is constructed based on the secondary development of ADAMS.Based on the platform,the developed aerodynamic model is verified, then the flight-folding process of the folding wing aircraft is simulated, and the influences of airfoil thickness on the results are investigated.Results show that the developed aerodynamic model can effectively describe the thickness effect of the folding wing.Airfoil thickness, which cannot be considered by the panel method, has a great influence on the hinge moments during the folding process, and the thickness correction has great significance in the calculation of folding wing's hinge moments. | Hao XU Jinglong HAN Haiwei YUN Xiaomao CHEN | 2020 | Chinese Journal of Aeronautics2020，33，3： | 1 |
| 5 | Application of Zero-Watermarking for Medical Image in Intelligent Sensor Network Security显示文摘The field of healthcare is considered to be the most promising application of intelligent sensor networks.However,the security and privacy protection ofmedical images collected by intelligent sensor networks is a hot problem that has attracted more and more attention.Fortunately,digital watermarking provides an effective method to solve this problem.In order to improve the robustness of the medical image watermarking scheme,in this paper,we propose a novel zero-watermarking algorithm with the integer wavelet transform(IWT),Schur decomposition and image block energy.Specifically,we first use IWT to extract low-frequency information and divide them into non-overlapping blocks,then we decompose the sub-blocks by Schur decomposition.After that,the feature matrix is constructed according to the relationship between the image block energy and the whole image energy.At the same time,we encrypt watermarking with the logistic chaotic position scrambling.Finally,the zero-watermarking is obtained by XOR operation with the encrypted watermarking.Three indexes of peak signal-to-noise ratio,normalization coefficient(NC)and the bit error rate(BER)are used to evaluate the robustness of the algorithm.According to the experimental results,most of the NC values are around 0.9 under various attacks,while the BER values are very close to 0.These experimental results show that the proposed algorithm is more robust than the existing zero-watermarking methods,which indicates it is more suitable for medical image privacy and security protection. | Shixin Tu Yuanyuan Jia Jinglong Du Baoru Han | 2023 | Computer Modeling in Engineering & Sciences2023，，7： | 0 |
| 6 | Dynamic Pricing Model of E-Commerce Platforms Based on Deep Reinforcement Learning显示文摘With the continuous development of artificial intelligence technology,its application field has gradually expanded.To further apply the deep reinforcement learning technology to the field of dynamic pricing,we build an intelligent dynamic pricing system,introduce the reinforcement learning technology related to dynamic pricing,and introduce existing research on the number of suppliers(single supplier and multiple suppliers),environmental models,and selection algorithms.A two-period dynamic pricing game model is designed to assess the optimal pricing strategy for e-commerce platforms under two market conditions and two consumer participation conditions.The first step is to analyze the pricing strategies of e-commerce platforms in mature markets,analyze the optimal pricing and profits of various enterprises under different strategy combinations,compare different market equilibriums and solve the Nash equilibrium.Then,assuming that all consumers are naive in the market,the pricing strategy of the duopoly e-commerce platform in emerging markets is analyzed.By comparing and analyzing the optimal pricing and total profit of each enterprise under different strategy combinations,the subgame refined Nash equilibrium is solved.Finally,assuming that the market includes all experienced consumers,the pricing strategy of the duopoly e-commerce platform in emerging markets is analyzed. | Chunli Yin Jinglong Han | 2021 | Computer Modeling in Engineering & Sciences2021，，4： | 0 |
| 7 | Neural mechanisms of top-down divided and selective spatial attention in visual and auditory perception显示文摘Top-down attention mechanisms require the selection of specificobjects or locations;however,the brain mechanism involved when attention is allocated across different modalities is not well understood.The aim of this study was to use functional magnetic resonance imaging to define the neural mechanisms underlyingdivided and selective spatial attention.A concurrent audiovisual stimulus was used,and subjects were prompted to focus on a visual,auditory and audiovisual stimulus in a Posner paradigm.Ourbehavioral results confirmed the better performance of selectiveattention compared to devided attention.We found differences in the activation level of the frontoparietal network,visual/auditorycortex,the putamen and the salience network under differentattention conditions.We further used Granger causality(GC)toexplore effective connectivity differences between tasks.Differences in GC connectivity between visual and auditory selective tasksreflected the visual dominance effect under spatial attention.In addition,our results supported the role of the putamen inredistributing attention and the functional separation of the saliencenetwork.In summary,we explored the audiovisual top-down allocation of attention and observed the differences in neuralmechanisms under endogenous attention modes,which revealedthe differences in cross-modal expression in visual and auditory attention under attentional modulation. | Zhongtian Guan Meng Lin Qiong Wu Jinglong Wu Kewei Chen Hongbin Han Dehua Chui Xu Zhang Chunlin Li | 2023 | Brain Science Advances2023，9，2： | 0 |
| 8 | Multimodal biofeedback for Parkinson’s disease motor and nonmotor symptoms显示文摘Parkinson’s disease(PD)is a neurodegenerative disordercharacterized by motor retardation,myotonia,quiescent tremor,and postural gait abnormality,as well as nonmotor symptoms such asanxiety and depression.Biofeedback improves motor and nonmotorfunctions of patients by regulating abnormal electroencephalogram(EEG),electrocardiogram(ECG),photoplethysmography(PPG),electromyography(EMG),respiration(RSP),or other physiologicalsignals.Given that multimodal signals are closely related to PDstates,the clinical effect of multimodal biofeedback on patientswith PD is worth exploring.Twenty-one patients with PD in Beijing Rehabilitation Hospital were enrolled and divided into threegroups:multimodal(EEG,ECG,PPG,and RSP feedback signal),EEG(EEG feedback signal),and sham(random feedback signal),and they received biofeedback training five times in two weeks.The combined clinical scale and multimodal signal analysis resultsrevealed that the EEG group significantly improved motor symptomsand increased Berg balance scale scores by regulatingβband activity;the multimodal group significantly improved nonmotorsymptoms and reduced Hamilton rating scale for depression scores by improvingθband activity.Our preliminary results revealed thatmultimodal biofeedback can improve the clinical symptoms of PD,but the regulation effect on motor symptoms is weaker than that ofEEG biofeedback. | Zhongyan Shi Lei Ding Xingyu Han Bo Jiang Jiangtao Zhang Dingjie Suo Jinglong Wu Guangying Pei Boyan Fang Tianyi Yan | 2023 | Brain Science Advances2023，9，2： | 0 |
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