Spatial Characteristics and Driving Forces of Cultivated Land Changes by Coupling Spatial Autocorrelation Model and Spatial-temporal Big Data

( Wang Hua ),( Zhu Yuxin ),( Wang Mengyu ),( Niu Jiqiang ),( Chen Xueye ),( Zhang Yang ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.2

With the rapid development of information technology, it is now possible to analyze the spatial patterns of cultivated land and its evolution by combining GIS, geostatistical analysis models and spatiotemporal big data for the dynamic monitoring and management of cultivated land resources. The spatial pattern of cultivated land and its evolutionary patterns in Luoyang City, China from 2009 to 2019 were analyzed using spatial autocorrelation and spatial autoregressive models on the basis of GIS technology. It was found that: (1) the area of cultivated land in Luoyang decreased then increased between 2009 and 2019, with an overall increase of 0.43% in 2019 compared to 2009, with cultivated land being dominant in the overall landscape of Luoyang; (2) cultivated land holdings in Luoyang are highly spatially autocorrelated, with the ‘high-high’-type area being concentrated in the border area directly north and northeast of Luoyang, while the ‘low-low’-type area is concentrated in the south and in the municipal area of Luoyang, and being heavily influenced by topography and urbanization. The expansion determined during the study period mainly took place in the Luoyang City, with most of it being transferred from the ‘high-low’-type area; (3) elevation, slope and industrial output values from analysis of the bivariate spatial autocorrelation and spatial autoregressive models of the drivers all had significant effects on the amount of cultivated land holdings, with elevation having a positive effect, and slope and industrial output having a negative effect.

Zoning Permanent Basic Farmland Based on Artificial Immune System coupling with spatial constraints

( Wang Hua ),( Wang Mengyu ),( Zhu Yuxin ),( Niu Jiqiang ),( Chen Xueye ),( Zhang Yang ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.5

The red line of Permanent Basic Farmland is the most important part in the “three-line” demarcation of China’s national territorial development plan. The scientific and reasonable delineation of the red line is a major strategic measure being taken by China to improve its ability to safeguard the practical interests of farmers and guarantee national food security. The delineation of Permanent Basic Farmland zoning (DPBFZ) is essentially a multi-objective optimization problem. However, the traditional method of demarcation does not take into account the synergistic development goals of conservation of cultivated land utilization, ecological conservation, or urban expansion. Therefore, this research introduces the idea of artificial immune optimization and proposes a multi-objective model of DPBFZ red line delineation based on a clone selection algorithm. This research proposes an objective functional system consisting of these three sub-objectives: optimal quality of cropland, spatially concentrated distribution, and stability of cropland. It also takes into consideration constraints such as the red line of ecological protection, topography, and space for major development projects. The mathematical formal expressions for the objectives and constraints are given in the paper, and a multi-objective optimal decision model with multiple constraints for the DPBFZ problem is constructed based on the clone selection algorithm. An antibody coding scheme was designed according to the spatial pattern of DPBFZ zoning. In addition, the antibody-antigen affinity function, the clone mechanism, and mutation strategy were constructed and improved to solve the DPBFZ problem with a spatial optimization feature. Finally, Tongxu County in Henan province was selected as the study area, and a controlled experiment was set up according to different target preferences. The results show that the model proposed in this paper is operational in the work of delineating DPBFZ. It not only avoids the adverse effects of subjective factors in the delineation process but also provides multiple scenarios DPBFZ layouts for decision makers by adjusting the weighting of the objective function.

Disturbance Attenuation in Linear Systems Revisited

Jiqiang Wang,Hong Yue,Georgi Dimirovski 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.4

A variety of methods have been proposed for attenuating or rejecting disturbances in linear systems. Most of the approaches, however, are targeting the performance either near resonance or across the whole frequencyrange. Weighting functions can be utilized to shape the frequency response function over target frequencyband but they are usually of rule-of-thumb nature. A methodology is necessitated for designing controllers withperformance specified at any discrete frequency or over any desired frequency band. The paper aims to developsuch a methodology. Besides this, the proposed method can tell performance limitations and determine the problemof existence of optimal controllers, as well as providing a useful framework to improve the performance of anexisting controller. A number of important results are obtained and these results are subsequently validated througha practical application to a rotor blade example.

High-speed Rotor’s Mechanical Design and Stable Suspension Based on Inertia-ratio for Gyroscopic Effect Suppression

Jiqiang Tang,Shaopu Zhao,Ying Wang,Kuo Wang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

The rotor’s stable suspension is one of significant requirements for a magnetically suspended control momentum gyroscope (MSCMG), the gyroscopic effect is one of rotor’s prominent characteristics. To find out the relationship between rotor’s structure and gyroscopic effect, the inertia-ratio is originally presented and the relationship between the inertia-ratio and gyroscopic effects is researched. To improve the rotor’s suspension stability, the cross feedback control (CFC) method is researched based on modeling the suspension system of rotor and point out that only distributed PID control cannot make rotor’s suspension be stable due to the whirling. To suppress the gyroscopic effects more effectively and sustain the stable suspension within a wider speed range, a CFC method with pre-modulated gains is presented. All research results verify that this presented CFC method can effectively suppress the rotor’s vibration caused by its gyroscopic effects. Experimental results also indicate that a large inertiaratio is helpful to suppress rotor’s gyroscopic effect and can enhance the suspension stability to some extent. In addition, a rotor with angular momentum 200 Nms is designed for a MSCMG by optimizing its inertia-ratio. This paper will provide helpful hint for the research of high-speed rotor’s mechanical design and stable suspension.

Gimballing Flywheel and its Novel Reluctance Force-type Magnetic Bearing with Low Eddy Loss and Slight Tilting Torque

Jiqiang Tang,Chun’e Wang,Biao Xiang 한국자기학회 2013 Journal of Magnetics Vol.18 No.4

For magnetically suspended flywheel (MSFW) with gimballing capability, demerits of Lorentz force-type magnetic bearings and common reluctance force-type magnetic bearings are analyzed, a novel reluctance forcetype magnetic bearing (RFMB) including radial and axial magnetic bearing units with 4 separate biased permanent magnets and two conical stators is presented. By equivalent magnetic circuits’ method, its magnetic properties are analyzed. To reduce the eddy loss, it was designed as radial poles with shoes and its rotor made of Iron-based amorphousness. Although the uniformity of magnetic flux density in the conical air gap determines mainly the additional tilting torque, the maximum additional tilting torques is 0.05Nm and the rotor tilting has no influence on its forces when the rotor tilts or the maximum changes does not exceed 14% when the rotor drifts and tilts simultaneously. The MSFW with this RFMB can meet the maneuvering requirement of spacecraft theoretically.

Design and performance analysis of magnetorheological grease flexible manipulator gripper

Xudan Ye,Jiqiang Dong,Wenchao Wang,Jing Lu,Jiong Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.3

To address the issue of traditional manipulators being unable to grasp and operate objects of varying shapes or easily damaged objects in some work scenes, a new type of flexible manipulator with magnetorheological grease based on the magnetorheological effect was developed. Comsol was used to simulate the magnetic field of the flexible gripper. The results showed that as coil current increased, the magnetic induction intensity increased, the magnetic induction line began to close to the rubber capsule after the shell support was added, the magnetorheological grease solidified after the magnetic field was applied, and the object could be wrapped and grasped. Then the kinematics and grasping ability of the flexible manipulator with magnetorheological grease in the grasping process are analyzed. Finally, an experimental test platform for the magnetorheological grease flexible manipulator is built, and under different currents (0 A, 0.25 A, 0.5 A, 0.75 A, 1 A), the flexible manipulator is tested for different gripping depths (6 mm, 11 mm, 17.5 mm) and a variety of diameter wooden balls (15 mm, 40 mm, 60 mm) gripping ability. The results show that when the gripping depth is constant, the envelope angle of the flexible fingertip to the sphere decrease with the increase of the diameter of the sphere, and when the diameter of the sphere is constant, the higher the grasping depth of the flexible fingertip, the larger the envelope angle to the sphere.

Elastic-plastic-creep response of multilayered systems under cyclic thermo-mechanical loadings

Xiaotao Zheng,Jiqiang Wang,Wei Wang,Linwei Ma,Wei Lin,Jiuyang Yu 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.3

The modified Ohno and Abdel-Karim nonlinear kinematic hardening model considering cyclic hardening and creep effect are developed to investigate the deformation and residual stress of multilayered systems subjected to cyclic thermal and mechanical loads. Results reveal that, if the creep behavior is considered, significant stress relaxation takes place during about the first several cycles, and the accumulated strain of multilayered systems under deformation-controlled loads finally remains constant, which leads to shakedown. Remarkable changes of the residual stress, location of neutral axis and curvature of Si-Cu beams are observed during about the first 100 cycles. Therefore, the proposed model can be used for the engineering design of multilayered systems under complex loads.