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Solar sail attitude control using shape variation of booms

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Chinese Journal of Aeronautics 2022年第10期35卷 326-336页

作者： Feng ZHANG Shengping gong Haoran gong Hexi BAOYIN School of Aerospace Engineering Tsinghua UniversityBeijing 100084China School of Astronautics Beihang UniversityBeijing 100083China

Active attitude control of solar sails is required to control the direction of the force generated by Solar Radiation Pressure(SRP). It is desirable to control the attitude through propellantfree means. This paper proposes a new method for attitude control of solar sails: A boom consisting of "smart" structural material can be deformed by the piezoelectric actuator, and Solar Radiation Pressure torque will be generated due to shape variation of sail membrane caused by boom deformation. The method has the advantages of simple structure, small disturbance and small additional load, and is not limited by the size of the solar sail. The case of rendezvous with the Asteroid 2000SG344 is used to verify the attitude control around the pitch and yaw axes.

关键词： Attitude control Boom deformation Dynamics Solar radiation pressure Solar sail

Extrapolation of upwelling irradiance just beneath the ocean surface from the in-water radiometric profile measurements

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Journal of Oceanology and Limnology 2023年第5期41卷 1694-1705页

作者： Shaoqi gong School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044China

Accurate measurements of upwelling irradiance just beneath the ocean surface,E_(u)(λ,0^(-)),can be used to calculate ocean optical parameters,and further develop retrieval algorithms for remotely sensing water component *** to the effects of sea surface waves,perturbation from instrument platform(ship),and instrument self-shading,E_(u)(λ,0^(-))is often difficult to be accurately *** study presents a procedure for extrapolating the E_(u)(λ,0^(-))from the in-water radiometric profile *** the optical profile data from 13 bands(ranging from 381 to 779 nm)measured by 45 casts in the Ligurian Sea during 2003–2009,the E_(u)(λ,0^(-))was extrapolated from in-water upwelling irradiance measurements between the initial shallow depth,Z_(0),and an optimal bottom depth,Z_(1),by three linear models(linear,2-degree polynomial,and exponential)and two nonlinear models(LOESS and spline).The accumulated errors of extrapolated E_(u)(λ,0^(-))at each wavelength for the five models were *** was found that the optimal Z_(1) depth for the linear and exponential models was at the depth of80%of E_(u)(λ,Z_(0)),50%of E_(u)(λ,Z_(0))for the 2-degree polynomial model,40%of E_(u)(λ,Z_(0))for the LOESS model,and 15%of E_(u)(λ,Z_(0))for the spline *** extrapolated E_(u)(λ,0^(-))derived from the five models was in good agreement with the calculated true E_(u)(λ,0^(-)).In all bands,the 2-degree polynomial model achieved the highest accuracy,followed by the LOESS *** the short band of 381–559 nm,the linear and exponential models had the third-best performance,and the spline model performed worst within this *** the red band of 619–779 nm,the accuracies of the exponential and spline models had the third highest performance,and the linear model produced lowest ***,the 2-degree polynomial model was an optimal procedure for extrapolation of E_(u)(λ,0^(-))from the in-water radiometric profile measurements.

关键词： extrapolation upwelling irradiance ocean in-water accuracy

Organic field-effect optical waveguides: a new break-through all organic optoelectronics

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Science China Chemistry 2019年第3期62卷 293-294页

作者： Xiong gong College of Polymer Science and Polymer Engineering The University of Akron

Optical waveguide, a physical structure that guides electromagnetic waves in the optical spectrum, is the key elements of photonic devices that perform guiding, coupling, switching, splitting, multiplexing and demultiplexing of optical signals [1]. In general, an optical waveguide is tuned by electrical field through a two-terminal diode [1]. Such integration was widely used in current photonic devices, but restricts its potentials in tiny optical chips for bio/medical and space applications [2].

关键词： Optical physical structure electromagnetic

Adaptive tracking control for air-breathing hypersonic vehicles with state constraints

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Frontiers of Information Technology & Electronic Engineering 2017年第5期18卷 599-614页

作者： gong-jun LI Science and Technology on Space Intelligent Control Laboratory Beijing Institute of Control EngineeringBeijing 100190China

We investigate the adaptive tracking problem for the longitudinal dynamics of state-constrained airbreathing hypersonic vehicles, where not only the velocity and the altitude, but also the angle of attack(AOA) is required to be tracked. A novel indirect AOA tracking strategy is proposed by viewing the pitch angle as a new output and devising an appropriate pitch angle reference trajectory. Then based on the redefined outputs(i.e., the velocity,the altitude, and the pitch angle), a modified backstepping design is proposed where the barrier Lyapunov function is used to solve the state-constrained control problem and the control gain of this class of systems is *** analysis is given to show that the tracking ob jective is achieved, all the closed-loop signals are bounded,and all the states always satisfy the given constraints. Finally, numerical simulations verify the effectiveness of the proposed approach.

关键词： Hypersonic vehicle Constraints Output redefinition Barrier Lyapunov function

Microbial safety control of compost material with cow dung by heat treatment

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Journal of Environmental Sciences 2007年第8期19卷 1014-1019页

作者： gong Chun-ming Xiamen Environmental Protection Research Institute Xiamen 361006 China. Laboratory of Soil Microbiology Faculty of Agriculture Saga University Saga840-8502 Japan

Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.

关键词： microbial safety control pathogenic bacteria compost cow dung heat treatment

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高强度混凝土结构施工技术及性能优化

山西建筑 2025年第2期51卷 104-106,111页

作者：宫钦寿山东省青岛市莱西市房产发展服务中心山东青岛266600

结合工程案例,介绍了高强度混凝土材料的特性表现,从强度提升、收缩变形、抗渗性能、抗裂性能等方面论述了高强度混凝土结构的优化策略,从配合设计、搅拌工艺、浇筑及养护技术等方面探讨了施工技术的改进措施,从而保证高强度混凝土结构... 详细信息

结合工程案例,介绍了高强度混凝土材料的特性表现,从强度提升、收缩变形、抗渗性能、抗裂性能等方面论述了高强度混凝土结构的优化策略,从配合设计、搅拌工艺、浇筑及养护技术等方面探讨了施工技术的改进措施,从而保证高强度混凝土结构的整体性能和施工质量。

关键词：高强度混凝土性能优化配合比复合养护

Human Following for Outdoor Mobile Robots Based on Point-Cloud's Appearance Model

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Chinese Journal of Electronics 2021年第6期30卷 1087-1095页

作者： gong Linxi CAI Yunfei School of Computer Science and Engineering Nanjing University of Science and Technology

In this paper, we propose a point-cloudbased algorithm for human-following robots to detect and follow the target person in a complex outdoor environment. Specifically, we exploit Ada Boost to train a binary classifier in a designed feature space based on sparse point-cloud to distinguish the target person from other objects. Then a particle filter is applied to continuously track the target’s position. Motivated by the interference of obstacles in long-distance human-following scenarios, a motion plan algorithm based on vector field histogram is adopted. Experiments are carried out both on the dataset we collected and in real application scenarios. The results show that our algorithm has the ability of real-time target detection and tracking, and is robust to deal with complex situations in outdoor environments.

关键词： outdoor environments outdoor mobile robots particle filter target person point-cloud-based algorithm path planning collision avoidance designed feature space binary classifier mobile robots tracking real-time target detection particle filtering (numerical methods) sparse point-cloud learning (artificial intelligence) complex outdoor environment motion plan algorithm vector field histogram object detection

Investigation of exhaled pollutant distribution in the breathing microenvironment in a displacement ventilated room with indoor air stability conditions

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Journal of Environmental Sciences 2021年第1期33卷 336-345页

作者： Xiaorui Deng Guangcai gong Department of Civil Engineering Hunan UniversityChangsha 410082China Key Laboratory of Building Safety and Energy Efficiency Ministry of EducationHunan UniuersityChangsha 410082China

This study experimentally studied the dispersion of exhaled pollutant in the breathing microenvironment(BM)in a room equipped with a displacement ventilation(DV)system and indoor air stability conditions(i.e.,stable and unstable conditions).The vertical temperature differences and the carbon dioxide(CO_(2))concentration in the BM were *** show that when DV is combined with the stable condition(DS),pollutant tends to accumulate in the BM,leading to a high pollutant concentration in this ***,when DV is combined with the unstable condition(DU),pollutant diffuses to a relatively wider area beyond the BM,thus the pollutant concentration in the BM is substantially ***,increasing the flow rate can reduce the pollutant concentration in the BM of the DS but yields little difference of the *** addition,personal exposure intensity increases with time,and the DS has a relatively higher increase rate than *** results suggest that indoor air stability will affect the performance of DV *** will lead to a higher health risk for people when they stay in the indoor environment with pollutant sources,and DU is recommended for minimizing pollutant level in the BM in order to reduce the pollutant concentration and providing better air environments for the occupants.

关键词： Displacement ventilation Indoor air stability Human breathing microenvironment Personal exposure

Coalitional Equilibria in Coalitional Abstract Economies with Nonordered Preferences

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Journal of Systems Science & Complexity 2020年第1期33卷 137-145页

作者： YANG Zhe gong Qingbin School of Economics Shanghai University of Finance and EconomicsShanghai 200433China Key Laboratory of Mathematical Economics(SUFE) Ministry of EducationShanghai 200433China

This paper investigates the existence of coalitional equilibria for coalitional abstract economies with nonordered ***,the authors give a fuzzy extension of the coalitional equilibrium existence *** main result is illustrated with applications to coalitional abstract economies with payoff functions,strong Nash equilibria and absolute optimal solutions.

关键词： Absolute optimal solution coalitional abstract economy coalitional equilibria equilibrium existence strong Nash equilibria