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Experimental Investigation on the Effect of Mainstream Turbulence on Full Coverage Film Cooling Effectiveness for a Turbine Guide Vane

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Journal of Thermal Science 2019年第1期28卷 145-157页

作者： FU Zhongyi ZHU Huiren CHENG Lijian jiang Ru School of Power and Energy Northwestern Polytechnical University

Experiments have been performed to investigate the effect of mainstream turbulence on the three-dimensional distribution of the full coverage film cooling effectiveness for two enlarged actual twisted vanes with cylindrical or shaped holes. The film cooling effectiveness was measured by transient liquid crystal technique at mainstream turbulence intensities of 2%, 9% and 15%. The mass flow rate ratios range from 5.5% to 12.5%. There are 3, 8 and 7 rows of film holes on the suction side, leading edge and pressure side, respectively. Results show that for the cylindrical hole vane the high mainstream turbulence intensity decreases the film cooling effectiveness in the top region and down region of pressure side in the low mass flow rate ratio of 5.5%, while the effect is opposite in the high mass flow rate ratio of 12.5%. The film cooling effectiveness in the middle region of pressure side decreases obviously with the increase of the turbulence at the low mass flow rate ratio of 5.5%, while the influence of increasing turbulence weakens gradually with the increase of mass flow rate ratio. Moreover, the high mainstream turbulence improves the film cooling effectiveness in the further downstream of the holes on suction side at the high mass flow rate ratio of 12.5%. For the shaped hole vane, the increase of mainstream turbulence decreases the film cooling effectiveness at all mass flow rate ratios. This study reveals the influence rule of the mainstream turbulence on the film cooling effectiveness in the different regions of the three-dimensional vane surface. The results would guide the designs of engineering heat transfer with application in gas turbine blade/vane cooling.

关键词： film cooling effectiveness turbulence intensity mass flow rate ratio turbine guide vane

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Fault-tolerant control with mixed aerodynamic surfaces and RCS jets for hypersonic reentry vehicles

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Chinese Journal of Aeronautics 2017年第2期30卷 780-795页

作者： He Jingjing Qi Ruiyun jiang Bin Zhai Rongyu College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 211106 China

This paper proposes a fault-tolerant strategy for hypersonic reentry vehicles with mixed aerodynamic surfaces and reaction control systems（RCS） under external disturbances and subject to actuator *** surfaces are treated as the primary actuator in normal situations,and they are driven by a continuous quadratic programming（QP） allocator to generate torque commanded by a nonlinear adaptive feedback control *** aerodynamic surfaces encounter faults,they may not be able to provide sufficient torque as commanded,and RCS jets are activated to augment the aerodynamic surfaces to compensate for insufficient *** loss of effectiveness and stuck faults are considered in this paper,and observers are designed to detect and identify the *** on the fault identification results,an RCS control allocator using integer linear programming（ILP） techniques is designed to determine the optimal combination of activated RCS *** treating the RCS control allocator as a quantization element,closed-loop stability with both continuous and quantized inputs is *** results verify the effectiveness of the proposed method.

关键词： Control allocation Fault-tolerant control Hypersonic vehicles Quantized control Reaction control system(RCS)

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Overview on the Development of Nanostructured Thermal Barrier Coatings

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Journal of Materials Science & Technology 2007年第4期23卷 449-456页

作者： Xianliang jiang2 Chunbo LIU Feng LIN School of Materials Science and Engineering Central South University Changsha 410083 China General Research Institute of Mining and Metallurgy Beijing 100044 China

Thermal barrier coatings （TBCs） have successfully been used in gas turbine engines for increasing operation temperature and improving engine efficiency. Over the past thirty years, a variety of TBC materials and TBC deposition techniques have been developed. Recently, nanostructured TBCs emerge with the potential of commercial applications in various industries. In this paper, TBC materials and TBC deposition techniques such as air plasma spray （APS）, electron beam physical vapor deposition （EB-PVD）, laser assisted chemical vapor deposition （LACVD） are briefly reviewed. Nanostructured 7-8 wt pct yttria stabilized zirconia （7-8YSZ）TBC by air plasma spraying of powder and new TBC with novel structure deposited by solution precursor plasma spray （SPPS） are compared. Plasma spray conditions, coating forming mechanisms, microstructures,phase compositions, thermal conductivities, and thermal cycling lives of the APS nanostructured TBC and the SPPS nanostructured TBC are discussed. Research opportunities and challenges of nanostructured TBCs deposited by air plasma spray are prospected.

关键词： Zirconia Thermal barrier coating Plasma spray Nanostructure

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Multi-feature-Based Subjective-Sentence Classification Method for Chinese Micro-blogs

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Chinese Journal of Electronics 2017年第6期26卷 1111-1117页

作者： ZHANG Yangsen ZHANG Yaorong jiang Yuru HUANG Gaijuan Beijing Information and Technology University

The accurate classification of subjective and objective sentences is important in the preparation for micro-blog sentiment analysis. Since a single feature type cannot provide enough subjective information for classification, we propose a Support vector machine(SVM)-based classification model for Chinese micro-blogs using multiple features. We extracted the subjective features from the Part of speech(POS) and the dependency relationship between words, and constructed a 3-POS subjective pattern set and a dependency template set. We fused these two types of features and used an SVM-based model to classify Chinese micro-blog text. The experimental results showed that the performance of the classification model improved remarkably when using multiple features.

关键词： Micro-blog sentiment analysis Subjective and objective classification Support vector machine(SVM) 3-POS subjective pattern set Dependency template set

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A Fast Approximation Method for Partially Observable Markov Decision Processes

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Journal of Systems Science & Complexity 2018年第6期31卷 1423-1436页

作者： LIU Bingbing KANG Yu jiang Xiaofeng QIN Jiahu Department of Automation University of Science and Technology of China

This paper develops a new lower bound method for POMDPs that approximates the update of a belief by the update of its non-zero *** uses the underlying MDP to explore the optimal reachable state space from initial belief and select actions during value iterations,which significantly accelerates the convergence ***,an algorithm which collects and prunes belief points based on the upper and lower bounds is presented,and experimental results show that it outperforms some of the state-of-art point-based algorithms.

关键词： Lower bound point-based POMDP

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A Video Watermarking DRM Method Based on H.264 Compressed Domain with Low Bit-Rate Increasement

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Chinese Journal of Electronics 2016年第4期25卷 641-647页

作者： MA Zhaofeng HUANG Jianqing jiang Ming NIU Xinxin Information Security Center of Beijing University of Posts and Telecommunications Library of Beijing University of Posts and Telecommunications Audio and Video Department the Third Research Institute of China Electronics Technology Group Corporation

It gets more and more important for video copyright protection,it is necessary to provide efficient H.264 compression domain watermarking for video Digital rights management(DRM).A new watermarking method based on H.264 compressed domain is proposed for video DRM,in which the embedding and extracting procedure are performed using the syntactic elements of the compressed bit *** this way,complete decoding is unnecessary in both embedding and extracting *** on the analysis of the time and space,some appropriate sub-blocks are selected for embedding watermarks,increasing watermark robustness while reducing the declination of the visual *** order to avoid bit-rate increasing and strengthen the security of the proposed video watermarking scheme,only a set of nonzero coefficients quantized in different parts of macroblocks is chosen for inserting *** experiment results show the proposed scheme can achieve excellent robustness against some common attacks,the proposed scheme is secure and efficient for video content DRM protection.

关键词： Video watermarking H.264 Temporal quality Compressed domain watermarking

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Novel robust fault diagnosis method for flight control systems

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Journal of Systems Engineering and Electronics 2008年第5期19卷 1017-1023页

作者： Guo Yuying jiang Bin Zhang Youmin Wang dianfei Coll. of Automation Engineering Nanjing Univ. of Aeronautics and Astronautics Nanjing 210016 P. R. China Southwestern Univ. of Science and Technology Mianyang 621010 P. R. China Dept. of Mechanical and Industrial Engineering Concordia Univ. Montreal Quebec H3G 1M8 Canada

A novel robust fault diagnosis scheme, which possesses fault estimate capability as well as fault diagnosis property, is proposed. The scheme is developed based on a suitable combination of the adaptive multiple model （AMM） and unknown input observer （UIO）. The main idea of the proposed scheme stems from the fact that the actuator Lock-in-Place fault is unknown （when and where the actuator gets locked are unknown）, and multiple models are used to describe different fault scenarios, then a bank of unknown input observers are designed to implement the disturbance de-coupling. According to Lyapunov theory, proof of the robustness of the newly developed scheme in the presence of faults and disturbances is derived. Numerical simulation results on an aircraft example show satisfactory performance of the proposed algorithm.

关键词： fault diagnosis adaptive multiple model unknown input observer flight control.

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Online Pareto optimal control of mean-field stochastic multi-player systems using policy iteration

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Science China(Information Sciences) 2024年第4期67卷 21-37页

作者： Xiushan jiang Yanshuang WANG Dongya ZHAO Ling SHI College of New Energy China University of Petroleum(East China) Department of Electronic and Computer Engineering Hong Kong University of Science and Technology

In this study, the Pareto optimal strategy problem was investigated for multi-player mean-field stochastic systems governed by It? differential equations using the reinforcement learning(RL) method.A partially model-free solution for Pareto-optimal control was derived. First, by applying the convexity of cost functions, the Pareto optimal control problem was solved using a weighted-sum optimal control problem. Subsequently, using on-policy RL, we present a novel policy iteration(PI) algorithm based on the Hrepresentation technique. In particular, by alternating between the policy evaluation and policy update steps,the Pareto optimal control policy is obtained when no further improvement occurs in system performance,which eliminates directly solving complicated cross-coupled generalized algebraic Riccati equations(GAREs).Practical numerical examples are presented to demonstrate the effectiveness of the proposed algorithm.

关键词： mean-field stochastic systems Pareto optimal control policy iteration scheme ℌ-representation

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Flatness Control Based on Dynamic Effective Matrix for Cold Strip Mills

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Chinese Journal of Mechanical Engineering 2009年第2期22卷 287-296页

作者： LIU Hongmin HE Haitao SHAN Xiuying jiang Guangbiao Engineering Research Center of Rolling Equipment and Complete Technology of Ministry of Education Yanshan University Qinhuangdao 066004 China State Key Laboratory of Metastable Materials Science ＆ Technology Yanshan University Qinhuangdao 066004 China College of Information Science and Engineering Yanshan University Qinhuangdao 066004 China Baogang Branch Baoshan Iron and Steel Co. Ltd. Shanghai 200941 China

Steel strips are the main of steel products and flatness is an important quality indicator of steel strips. Flatness control is the key and highly difficult technique of strip mills. The bottle-neck restricting the improvement of flatness control techniques is that the research on flatness theories and control mathematic models is not in accordance with the requirement of technique developments. To build a simple, rapid and accurate explicit formulation control model has become an urgent need for the development of flatness control technique. This paper puts forward the conception of dynamic effective matrix based on the effective matrix method for flatness control proposed by the authors under the consideration of the influence of the change of parameters in roiling processes on the effective matrix, and the concept is validated by industrial productions. Three methods of the effective matrix generation are induced： the calculation method based on the flatness prediction model; the calculation method based on the data excavation in rolling processes and the direct calculation method based on the network model. A fuzzy neural network effective matrix model is built based on the clusters, and then the network structure is optimized and the high-speed-calculation problem of the dynamic effective matrix is solved. The flatness control scheme for cold strip mills is proposed based on the dynamic effective matrix. On stand 5 of the 1 220 mm five-stand 4-high cold strip tandem mill, the industrial experiment with the control methods of tilting roll and bending roll is done by the control scheme of the static effective matrix and the dynamic effective matrix, respectively. The experiment result proves that the control effect of the dynamic effective matrix is much better than that of the static effective matrix. This paper proposes a new idea and method for the dynamic flatness control in the rolling processes of cold strip mills and develops the theory and model of the fl

关键词： cold strip mill flatness control dynamic effective matrix cluster fuzzy neural network

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Identification and standardization of maneuvers based upon operational flight data

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Chinese Journal of Aeronautics 2015年第1期28卷 133-140页

作者： Wang Yongjun Dong jiang Liu Xiaodong Zhang Lixin Chengdu Aircraft Design & Research Institute

To find a way of loads analysis from operational flight data for advanced aircraft,maneuver identification and standardization jobs are conducted in this paper. For thousands of sorties from one aircraft, after studying the flight attitude when performing actions, the start and end time of the maneuvers can be determined. According to those time points, various types of maneuvers during the flight are extracted in the form of multi-parameters time histories. By analyzing the numerical range and curve shape of those parameters, a characteristic data library is established to model all types of maneuvers. Based on this library, a computer procedure using pattern-recognition theory is programmed to conduct automatic maneuver identification with high accuracy. In that way, operational loads are classified according to maneuver type. For a group of identified maneuvers of the same type, after the processes of time normalization, trace shifting, as well as averaging and smoothing, the idealization standard time history of each maneuver type is ***, the typical load statuses are determined successfully based on standard maneuvers. The proposed method of maneuver identification and standardization is able to derive operational loads effectively, and might be applied to monitoring loads in Individual Aircraft Tracking Program（IATP）.

关键词： operational aircraft maneuver library smoothing performing attitude programmed Split conduct

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