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Design for aircraft engine multi-objective controllers with switching characteristics

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Chinese Journal of Aeronautics 2014年第5期27卷 1097-1110页

作者： Liu Xiaofeng Shi jing Qi Yiwen Yuan ye School of Transportation Science and Engineering Beihang University School of Automation Shenyang Aerospace University School of Energy and Power Engineering Beihang University

The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formulated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.

关键词： Aircraft engine Compensatory controller Min/Max switching Multi-objectives control Smooth switching Switching scheme

Fault tolerance on-chip: a reliable computing paradigm using self-test, self-diagnosis, and self-repair (3S) approach

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Science China(Information Sciences) 2018年第11期61卷 31-47页

作者： Xiaowei LI Guihai YAN jing ye Ying WANG State Key Laboratory of Computer Architecture Institute of Computing TechnologyChinese Academy of Sciences University of Chinese Academy of Sciences

If your computer crashes, you can revive it by a reboot, an empirical solution that usually turns out to be effective. The rationale behind this solution is that transient faults, either in hardware or software,can be fixed by refreshing the machine state. Such a "silver bullet", however, could be futile in the future because the faults, especially those existing in the hardware such as Integrated Circuit(IC) chips, cannot be eliminated by refreshing. What we need is a more sophisticated mechanism to steer the system back to the right track. The "magic cure" is the Fault Tolerance On-Chip(FTOC) mechanism, which relies on a suite of built-in design-for-reliability logic, including fault detection, fault diagnosis, and error recovery, working in a self-supportive manner. We have exploited the FTOC to build a holistic solution ranging from on-chip fault detection to error recovery mechanisms to address faults caused by chips progressively aging. Besides fault detection, the FTOC paradigm provides attractive benefits, such as facilitating graceful performance degradation, mitigating the impact of verification blind spots, and improving the chip yield.

关键词： fault tolerance on-chip self-test self-diagnosis self-repair

An adaptive fuzzy filter for coding artifacts removal in video and image

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 841-848页

作者： WU jing ye Xiu-qing GU Wei-kang Department of Information and Communication Engineering Zhejiang University Hangzhou 310027 China

This paper proposes a new adaptive post-filtering algorithm to remove coding artifacts in block-based video coder. The proposed method concentrates on blocking and ringing artifacts removal. For de-blocking, the blocking strength is identified to determine the filtering range, and the maximum quantization parameter of the image is used to adapt the 1D fuzzy filter. For de-ringing, besides the edge detection, a complementary ringing detection method is proposed to locate the neglected ringing blocks, and the gradient threshold is adopted to adjust the parameter of 2D fuzzy filter. Experiments are performed on the MPEG-4 sequences. Compared with other methods, the proposed one achieves better detail preservation and artifacts removal performance with lower computational cost.

关键词： Adaptive fuzzy filter Blocking artifacts Ringing artifacts De-blocking De-ringing

Two types of mirror mode waves in the Kronian magnetosheath

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Earth and Planetary Physics 2023年第3期7卷 414-420页

作者： XinYa Duanmu ZhongHua yao Yong Wei ShengYi ye Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Department of Earth and Space Sciences Southern University of Science and TechnologyShenzhen Guangdong 518055China

A mirror mode wave is a fundamental magnetic structure in the planetary space environment that is persistently compressed by solar wind,especially in the *** modes have been widely identified in the magnetosheaths of the Earth and other planets in the solar system,yet the understanding of mirror mode waves on extraterrestrial planets is not as comprehensive as that on the *** magnetic field data collected by the Cassini spacecraft,we found peak and dip types according to the magnetic morphology(i.e.,structures with higher or lower magnetic strengths than the background field).Moreover,mirror mode waves and electromagnetic ion cyclotron waves were found one after the other,implying that the two wave modes may evolve into one another in the Kronian *** results indicate that many fundamental plasma processes associated with the mirror mode structure exist in the Kronian *** energy conversion in Saturn’s magnetosheath may provide key insights that will aid in understanding giant planetary magnetospheric processes.

关键词： mirror mode wave Cassini Kronian magnetosheath electromagnetic ion cyclotron wave

The spatiotemporal analysis of the population migration network in China,

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Infectious Disease Modelling 2023年第4期8卷 1117-1126页

作者： Wenjie Li ye yao Department of Biostatistics School of Public HealthFudan UniversityShanghaiChina Key Laboratory of Public Health Safety of Ministry of Education Fudan UniversityShanghaiChina

Population migration is a critical component of large-scale spatiotemporal models of infectious disease *** the most influential spreaders in networks is vital to controlling and understanding the spreading process of infectious *** used Baidu Migration data for the whole year of 2021 to build mobility *** nodes of the network represent cities,and the edges represent the population flow between *** applying the k-shell decomposition and the Louvain algorithm,we could get the k-shell values for each city and community ***,we identified the most efficient nodes or pathways in a complex network by generating random ***,we analyzed the eigenvalue of the migration matrix to find the nodes that have the most impact on the *** also found the consistency between k-shell value and eigenvalue through Kendall's t *** main result is that in Spring Festival and National Day,the network is at higher risk of an infectious disease outbreak and the Yangtze River Delta is at the highest risk of an epidemic all year *** is the most significant node in both k-shell value and eigenvalue *** spatiotemporal property of the network should be taken into account to model the transmission of infectious diseases more accurately.

关键词： K-shell decomposition Louvain algorithm Population mobility Infectious disease Network analysis

Development of a dual temperature control system for isoprene biosynthesis in Saccharomyces cerevisiae

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Frontiers of Chemical Science and Engineering 2022年第7期16卷 1079-1089页

作者： Jiaxi Lin Zhen yao Xiaomei Lyu Lidan ye Hongwei Yu Institute of Bioengineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310027China Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311200China Key Laboratory of Systems Microbial Biotechnology Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China School of Food Science and Technology Jiangnan UniversityWuxi 214122China

Conflict between cell growth and product accumulation is frequently encountered in the biosynthesis of secondary metabolites. To address the growth-production conflict in yeast strains harboring the isoprene synthetic pathway in the mitochondria, the dynamic control of isoprene biosynthesis was explored. A dual temperature regulation system was developed through engineering and expression regulation of the transcriptional activator Gal4p. A cold-sensitive mutant, Gal4ep19, was created by directed evolution of Gal4p based on an internally developed growth-based high-throughput screening method and expressed under the heat-shock promoter PSSA4 to control the expression of PGAL-driven pathway genes in the mitochondria. Compared to the control strain with constitutively expressed wild-type Gal4p, the dual temperature regulation strategy led to 34.5% and 72% improvements in cell growth and isoprene production, respectively. This study reports the creation of the first cold-sensitive variants of Gal4p by directed evolution and provides a dual temperature control system for yeast engineering that may also be conducive to the biosynthesis of other high-value natural products.

关键词： transcriptional activator directed evolution dynamic control heat-shock isoprene

Lithofacies identi cation using support vector machine based on local deep multi-kernel learning

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Petroleum Science 2020年第4期17卷 954-966页

作者： Xing-ye Liu Lin Zhou Xiao-Hong Chen jing-ye Li Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation College of Geology and EnvironmentXi’an University of Science and TechnologyXi’an 710054ShaanxiChina Hunan Provincial Key Laboratory of Shale Gas Resource Utilization Hunan University of Science and TechnologyXiangtan 411201HunanChina State Key Laboratory of Petroleum Resources and Prospecting National Engineering Laboratory for Ofshore Oil ExplorationChina University of Petroleum-BeijingBeijing 102249China

Lithofacies identification is a crucial work in reservoir characterization and *** vast inter-well area can be supplemented by facies identification of seismic ***,the relationship between lithofacies and seismic information that is affected by many factors is *** learning has received extensive attention in recent years,among which support vector machine(SVM) is a potential method for lithofacies *** classification involves identifying various types of lithofacies and is generally a nonlinear problem,which needs to be solved by means of the kernel ***-kernel learning SVM is one of the main tools for solving the nonlinear problem about ***,it is very difficult to determine the kernel function and the parameters,which is restricted by human ***,its computational efficiency is low.A lithofacies classification method based on local deep multi-kernel learning support vector machine(LDMKL-SVM) that can consider low-dimensional global features and high-dimensional local features is *** method can automatically learn parameters of kernel function and SVM to build a relationship between lithofacies and seismic elastic *** calculation speed will be expedited at no cost with respect to discriminant accuracy for multi-class lithofacies *** the model data test results and the field data application results certify advantages of the *** contribution offers an effective method for lithofacies recognition and reservoir prediction by using SVM.

关键词： Lithofacies discriminant Support vector machine Multi-kernel learning Reservoir prediction Machine learning

Economic and entropy production evaluation of extractive distillation and solvent-assisted pressure-swing distillation by multi-objective optimization

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Chinese Journal of Chemical Engineering 2023年第11期63卷 246-259页

作者： yao Wang Qing ye Jinlong Li Qingqing Rui Azhi Yu Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology School of Petrochemical EngineeringChangzhou UniversityChangzhou 213164China

Extractive distillation(ED)and solvent-assisted pressure-swing distillation(SA-PSD)are both special distillation processes that perform good at separating pressure-insensitive ***,few reported studies have compared the performance of the two *** this paper,ED processes with N-methylpyrrolidone(NMP)and dimethlac-etamide(DMCA)as entrainer,SA-PSD process with isopropyl-alcohol(IPA)as solvent and SA-PSD process with partial heat integration(PHI-PSD)are proposed to achieve high purity separation of a mixture of cyclohexane/2-butanol *** optimal operating conditions of the processes are obtained after optimizing with NSGA-Ⅱ algorithm when total annual cost(TAC)and the entropy production of process are set as *** optimal results show that the optimal PHI-PSD process has lower TAC by 28.7% and the lower entropy production by 39.5% than the optimal SA-PSD process while the ED process with NMP as entrainer has lower TAC by 50.9% and the lower entropy production by 56.1% than the optimal SA-PSD *** optimal results show that the ED process with NMP as entrainer has the best economic and thermodynamic efficiency among the four proposed processes in this paper.

关键词： Extractive distillation Solvent-assisted pressure-swing distillation Entropy production NSGA-Ⅱalgorithm Computer simulation

A multiwavelength study of the massive star-forming region IRAS 22506+5944

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Research in Astronomy and Astrophysics 2009年第12期9卷 1343-1350页

作者： Yuan-Wei Wu ye Xu Ji Yang jing-jing Li Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China Shanghai Observatory Chinese Academy of Sciences Shanghai 200030 China

We present a multi-line study of the massive star-forming region IRAS 22506＋5944. A new 6.7 GHz methanol maser was detected. ^12CO, 13CO, C180 and HCO＋ J = 1 - 0 transition observations reveal a star-formation complex consisting mainly of two cores. The dominant core has a mass of more than 200 Mo, while the other one is only about 35 340. Both cores are obviously at different evolutionary stages. A 12CO energetic bipolar outflow was detected with an outflow mass of about 15 Mo.

关键词： infrared: ISM - ISM: individual (IRAS 22506+5944) - ISM: jets andoutflows -- masers -- stars: formation