Physical Sciences and Mathematics Commons^™

Modelling Method Of Unmanned Vehicle Dynamics Based On Neural Network, Jun Wang, Min Liu, Xiaochuan Zhang, Yishan Ding, Juhui Feng, Ye Zhuang

Journal of System Simulation

Abstract: To address the challenges of high data acquisition costs of test data on dynamic characteristics between tires and soft terrain and low speed of numerical calculation for unmanned vehicles in complex terrestrial environments, a modeling method of unmanned vehicle dynamics based on a neural network was proposed. Tire-terrain contact dynamics models were built by using discrete element method (DEM) simulations for tire-terrain contact and experimental data, thereby creating a dataset of tire contact forces for various tire materials in terrestrial environments. The neural network was applied to regressively learn the dataset, and a nonlinear neural network tire model was …

Large-Scale Multi-Objective Evolutionary Algorithm Based On Multi-Region Dynamic Grouping, Binhao Liang, Jingxuan Wei, Fengqin Liang

Journal of System Simulation

Abstract: The decision variable dimension of large-scale multi-objective optimization problems can reach hundreds or even thousands. For existing large-scale multi-objective evolutionary algorithms based on decision variable analysis, which usually consume a large amount of computational resources for grouping and fail to consider the interactions between convergence-related variables and diversity-related variables, a large-scale multi-objective evolutionary algorithm based on multi-region adaptive dynamic grouping was proposed. The algorithm employed a Gaussian mixture model to partition the decision space into multiple regions; within each region, feature vectors were constructed for each decision variable, and spectral clustering was utilized to perform grouping. To validate …

Intelligent Competition Platform And Mode Driven By Cloud-Native Simulation, Long Qin, Hesong Huang, Lujia Yin, Chuan Ai, Qi Zhang, Xinmeng Li

Journal of System Simulation

Abstract: To solve the problems faced by the adversarial competition mode of agents, including difficult development and deployment, low resource utilization, poor reusability, and difficulty in accessing reinforcement learning algorithms, a new agent simulation training platform was designed. The software components of the competition platform were decoupled based on cloud-native technology; a high-performance simulation engine for the competition environment was proposed; a new method of an embedded reinforcement learning model for an intelligent control terminal was designed, with multiple online and offline policy-based reinforcement learning algorithms set. The experiment demonstrates that the development and deployment of the system is efficient, …

Intersection Positioning Algorithm With Spatial Translation Based On Sar Scene Matching, Cheng'en Pu, Yumin Lai, Rui Shi, Yan Liao, Kezi Meng, Lifeng Qu

Journal of System Simulation

Abstract: To address the problem that the positioning precision of the inertial navigation system cannot meet the requirements of autonomous positioning when the aircraft flies, an autonomous positioning method with spatial translation based on circular scanning scene matching of SAR was proposed. The spatial translation positioning model of the aircraft was established according to the position of the ground matching points obtained by single point and single circular scanning scene matching of SAR, the oblique distance between the matching points and the aircraft, and the inertial measurement information of the aircraft. The characteristic information of the matching point sequence was …

State Monitoring Of Nuclear Power Connection Sleeve Quality Inspection Equipment Driven By Digital Twin, Yandong Nan, Jinda Zhu, Xinbin Lu, Zhiying Qin, Dandan Qi, Zhiheng Ding

Journal of System Simulation

Abstract: To address the problems of delayed state perception, single monitoring dimension, and insufficient visualization in the quality inspection equipment for nuclear power connection sleeves, a state monitoring method driven by digital twin was proposed. A digital twin-based collaborative state monitoring framework for the inspection equipment was constructed. Based on the OPC UA technology, a multi-source information interconnection model was established. A finite state machine model was employed to discretize and logically drive the inspection process, and a hierarchical verification strategy was proposed to establish a multi-dimensional motion state monitoring mechanism. A surrogate model coupling the radial basis interpolation function …

Modeling And Simulation Of Target Characteristic Architecture Of Target Missile Based On Dodaf, Tuo Zhao, Yuqiao Liu, Yuan Ma, Yun Cheng, Shen Li

Journal of System Simulation

Abstract: In view of the problems of incomplete elements and missing architecture in the research of target characteristics of target missiles, this paper introduced the panoramic view, operational view, and capability view models in the DoDAF from the perspective of system engineering. According to the view development sequence of "panoramic description, operational decomposition, and capability matching", a target characteristic architecture of the target missile was constructed, which included target elements such as maneuvering characteristics and infrared radiation characteristics. The mapping relationship among "operational layer, capability layer, and target characteristic layer" of the target missile was obtained, and the architecture was …

Dynamic Model-Driven Verification Framework For Modular Aerial Bomb Systems, Wenlong Li, Shuhan Sang, Yusheng Liu, Haiyan He, Zan Liang, Wenqiang Yuan, Biao Niu, Weifeng Luo

Journal of System Simulation

Abstract: To address the problems of high verification costs, difficulty in covering dynamic behaviors, and lack of quantitative closed loops in the design stage of modular complex equipment, a dynamic model-driven modular system verification framework was proposed. Based on model-based systems engineering (MBSE) modeling, a structural coupling quantification model was constructed using the number of interfaces, signal interaction frequency, and dependency intensity. Dynamic tests were conducted in high-fidelity virtual simulation to collect data; performance rating for indicators such as accuracy, response, and stability, as well as system's comprehensive rating, were obtained, and the rating feedback was used for iterative optimization. …

Model-Based System Verification: Theoretical Framework, Key Technologies, And Future Prospects, Bo Sun, Yi Ren, Silin Wang, Qi Liu, Zhidong Li

Journal of System Simulation

Abstract: Traditional system verification methods face significant challenges in terms of efficiency, coverage, and traceability. To address these issues, this paper introduced model-based system verification (MBSV), which deeply integrated verification activities within the model-based systems engineering model system and evolution process. It presented the foundational logic of MBSV and proposed a multiview unified verification modeling strategy based on system modeling language (SysML), integrating requirements, structure, behavior, and constraints. The paper discussed the algorithms for selecting representative paths and reducing equivalent classes to enhance verification efficiency, the principles of test path search, as well as the intelligent path search mechanism based …

Space-Ground Integrated Collaborative Positioning Algorithm And Simulation For Trajectory Enhancement, Juhui Wei, Xinyong Zhang, Jiongqi Wang, Xuanying Zhou, Zhangming He

Journal of System Simulation

Abstract: To address the challenges of low credibility, weak consistency, and poor accuracy in the information of trajectory results from space-based and ground-based passive time difference positioning simulation systems, a space-ground integrated collaborative positioning method was proposed for trajectory enhancement. By analyzing the operating principle of the time difference positioning system, the influencing factors that measure positioning accuracy in different feature dimensions were obtained; spline smoothing was employed for data alignment between space-based and ground-based systems; a spline-constrained parametric trajectory model was proposed to further enhance the stability; an error-sensitive feature selection framework for improving simulation consistency was constructed to …

Science And Technology Empower New Quality Productive Forces To Promote Green Sustainable Development, Yongxiang Lu

Bulletin of Chinese Academy of Sciences (Chinese Version)

The rapid development of science and technology drives industrial innovation and upgrading, and promotes productive forces toward green, intelligent, and sustainable development. While improving production efficiency, new quality productive forces also promote green and sustainable development. This study reviews on green intelligent manufacturing technologies, green renewable energy technologies, green transportation technologies, and green data technologies, also explores their significance for global green and sustainable development.

Impact Of Climate Change On Agricultural Production In The North China Plain And Adaption Strategies, Yanjun Shen, Ying Guo, Chuanwei Zhang, Yaning Chen

Bulletin of Chinese Academy of Sciences (Chinese Version)

Over the past century, global warming has posed significant challenges to the North China Plain (NCP), a core region for grain production, where resource-induced water scarcity now coincides with complex meteorological disasters. In recent years, the NCP has exhibited new climatic characteristics, notably the transition from a “warm-dry” to a “warm-wet” pattern accompanied by asymmetric warming, leading to an increased frequency of extreme events such as droughts, abrupt dry-flood alternations, and temperature extremes. These shifts pose a grave threat to regional grain stability. Currently, critical gaps remain in the understanding of the underlying disaster mechanisms, as well as in predictive …

Impact And Countermeasures Of Climate Change On Grain Production In Northwest China, Qin’Ge Dong, Jianqiang He, Yi Li, Ning Yao, Xiang Li, Haolei Zhang, Shengnan Wang, Tengcong Jiang, Baiqing Chen, Chunrui Gao, Chao Liang, Guiyuan Zhang, Lei Gong, Jinxuan Zhao, Qiang Yu, Hao Feng

Bulletin of Chinese Academy of Sciences (Chinese Version)

Global climate change is reshaping the agricultural production patterns of grain crops in Northwest China. As an important reserve region for national grain production, Northwest China faces multiple uncertainties and compound risks in food security. This study analyzes the current status and limiting factors of grain production, along with regional climate change trends, and systematically evaluates the impacts of climate change and its associated disasters on the spatial distribution, cropping systems, and yield formation of major crops such as wheat, maize, and potato. Over the past 60 years, the region has experienced a warming rate of approximately 0.32℃ per decade …

Accelerating Marine Science And Technology Innovation Under Great Power Competition: Challenges And Recommendations, Qingbin Guo, Yongsha Xiong, Shifang Sun

Bulletin of Chinese Academy of Sciences (Chinese Version)

Against the backdrop of intensifying great-power competition, the core issues of global technological competition and cooperation are increasingly converging on the marine domain. The oceans are progressively becoming a critical strategic sphere for national development and security. At present, China is steadily advancing towards its goal of becoming a maritime power, achieving historic leaps in technological innovation such as shipbuilding and deep-sea exploration. Nevertheless, the path ahead for China’s marine science and technology innovation will inevitably face severe international circumstances and competition from established global maritime powers. Based on a review of global and Chinese progress in marine science and …

Construction Of China’S Marine Protected Area System In 15th Five-Year Plan, Ke Duan, Danhong Chen, Keqiang Li, Limin Han, Zhengyan Liu, Dongliang Lu, Xiulin Wang

Bulletin of Chinese Academy of Sciences (Chinese Version)

The establishment of the marine protected area (MPA) system constitutes a critical component of the national initiative to comprehensively advance the development of a nature reserve system centered on national parks. This study explores on domestic and international development trends from aspects such as conservation strategies, international policies, high seas protection, and development trends. It also sorts out and analyzes the construction status of marine protected area systems in China and the United States. Centering on issues in China related to spatial layout, management systems, policies and laws, scientific research support, high seas governance, and land-sea management, the study puts …

Strategic Talent Management In Era Of Intelligence And Digitalization: Current Situation And Path Exploration, Chaoying Tang, Chunyuan Wang

Bulletin of Chinese Academy of Sciences (Chinese Version)

The report of the 20th National Congress of the Communist Party of China emphasized “speed up efforts to build a contingent of personnel with expertise of strategic importance” to support China’s pursuit of high-level technological self-reliance and its goal of becoming a world-leading power in science and technology. The deep integration of digital and intelligent technologies is fundamentally transforming talent management paradigms and innovation processes, posing new demands on the knowledge structure, competency models, and management approaches of strategic talents. The study explores the concepts of strategic talent management in the digital intelligent era, establishes its logical framework, analyzes current …

Panoramic Analysis And Strategic Proposals Of Helium Research In China Based On Knowledge Graph, Huayang Li, Quanyou Liu, Dongya Zhu, Xiaoqi Wu, Chi Zhang, Zehui Shi

Bulletin of Chinese Academy of Sciences (Chinese Version)

Helium is a critical rare gas essential for aerospace, medical devices, and semiconductor production. With about 85% of its helium coming from imports, China’s advancement of exploration and development technologies is vital for national resource security. This study analyzes helium-related publications from CNKI (2000–2025) using advanced data visualization and statistical methods. It introduces a three-pronged approach–data-driven analysis, visual representation, and mechanistic explanation–to offer the first comprehensive examination of China’s helium exploration and development research, revealing its evolution and current state from multiple perspectives and providing fresh insights. By examining publication trends, institutional contributions, and evolving research priorities, the study maps …

Review On Optimization Of Simulation Modeling Strategies For Spacecraft Orbit Avoidance, Guozheng Li, Rui Wang, Shichao Fan, Xintong Cai, Xinyue Zhai

Journal of System Simulation

Abstract: The number of on-orbit spacecraft increases exponentially; the space environment becomes more complex, and the collision risk of on-orbit spacecraft increases significantly. On-orbit safety is thus severely threatened, posing higher requirements for orbit avoidance methods. The costs and risks of space activities are extremely high, making simulation an effective method to solve complex problems of orbit avoidance. The modeling, solution, and simulation methods for the two core issues of spacecraft orbit avoidance, "collision avoidance" and "pursuit-evasion games", were systematically reviewed, and the existing shortcomings were analyzed. The applications of technologies such as deep reinforcement learning in promoting orbit avoidance …

A Bilstm+Attention Method For Predicting The Intentions Of Air Combat Targets Based On Multi-Feature Continuous Time Series, Qiuni Li, Dong Wang, Chaozhe Wang, Zongcheng Liu

Journal of System Simulation

Abstract: To achieve advance prediction of enemy target intention, a three-layer air combat intention prediction method based on multi-feature continuous time series and BiLSTM+Attention, including trajectory prediction, threat assessment, and intention prediction was proposed. To prevent the onesidedness of intention prediction results caused by state information at a single moment, prediction was carried out from multiple state features and trajectory information in a continuous time series. An LSTM neural network was used to predict the trajectory of the target aircraft, and the threat assessment of the target aircraft before and after the prediction was conducted. The BiLSTM + Attention model …

Optimization Of Air Defense And Antimissile Firepower Resource Allocation Based On Adaptive Hybrid Evolution, Wei Liu, Delong Chen, Ze Liu, Rui Wang, Kaiwen Li, Tao Zhang

Journal of System Simulation

Abstract: Air defense and antimissile firepower resource allocation is a core optimization problem in modern defense systems. Under complex conditions such as spatiotemporal constraints and firepower resource limitations, this problem involves the optimal configuration of limited interceptors and belongs to the class of NP-hard multi-constrained combinatorial optimization problems. This paper established a comprehensive mathematical model encompassing range constraints, time window constraints, feasibility matrices, and interception probability models. To address the high-dimensional nonlinearity of the problem, an adaptive hybrid evolutionary algorithm (AHEA) was proposed. The algorithm integrated problem-aware initialization, adaptive parameter control, seven specialized neighborhood search operators, and an adaptive strategy …

Mechanism Analysis Of Parasitic Torque In Electric Loading Systems, Xiaozhe Sun, Zhenyu Fu, Zhaoke Xu, Jianxin Li

Journal of System Simulation

Abstract: To address the issues of sources and mechanisms of parasitic torque in electric loading systems for aircraft actuator loads, a functional model of the electric loading system was established. Numerical simulations and Monte Carlo methods were employed to analyze the sources of parasitic torque and its primary influencing factors. The influence mechanisms and degrees of the system's external inputs and internal disturbances on parasitic torque were analyzed and validated through single-parameter and multi-parameter analyses. The results indicate that parasitic torque is predominantly influenced by factors such as loading command frequency, sensor signal bias, and loading motor parameters. In particular, …

Simulation On Water Hammer Characteristics Of Bipropellant Attitude And Orbit Control Propulsion System, Xianwei Lang, Yantao Wang, Fang Zhang, Yizhen Zu, Xinyu Zhang, Weibin Xiang

Journal of System Simulation

Abstract: To address the water hammer problem in bipropellant attitude and orbit control propulsion systems during start-up, shutdown, and periodic operation, the water hammer characteristics under different operating conditions are investigated using simulation methods. The water hammer characteristics of annular and branched propellant delivery lines are compared, and the effects of multiengine interactions under various operating conditions, as well as the influence of water hammer on engine performance, are analyzed. The results show that the attenuation rate of pressure fluctuation in the annular pipeline system is significantly higher than that in the branch pipeline system. Under the condition of multi-cycle …

Design And Application Of Collaborative Simulation System For Satellite Constellation Flight Missions, Dong Yan, Hanzhe Yang, Fangfang Jiang, Chengbao Liu, Peng Zhang

Journal of System Simulation

Abstract: To meet the requirements of the collaborative drill for the ground operation and control system of the satellite constellation, as well as the verification and evaluation of in-orbit complex missions, the design ideas and implementation methods of the collaborative simulation system for satellite constellation flight missions were proposed. By adopting the time correction mechanism of the time-scale distributor, the time synchronization problem among the simulation nodes and the operation and control simulation system was solved. By adopting the communication technology based on improved PDXP + UDP, the problem of cross-node data interface and inter-satellite communication simulation was resolved. A …

Overall Design Method Of Low Earth Orbit Communication Satellite Based On Mbse, Jiace Shang, Rui Zhang, Ya Dai, Hua Zhu, Siqi Hu, Linqiang Ge, Chenguang Shi

Journal of System Simulation

Abstract: Drawing on the model-centric design philosophy of model-based systems engineering (MBSE), this study constructs a model architecture suitable for the design and analysis of low Earth orbit communication satellites. This architecture adopts a multi-dimensional matrix approach. Vertically, it traverses the mission layer, system layer, satellite general design layer, and subsystem layer, achieving top-down hierarchical decoupling. Horizontally, it establishes a comprehensive view mapping mechanism covering the domains of requirements, functions, structure, and performance. Integrating the characteristics of product development, a modeling process covering the entire lifecycle—from mission demonstration and overall design to subsystem design and integration verification—has been established. The …

Exploring Alternate Methods Of Flood Output Estimation During Natural Disasters, Finley Gardner

Honors College Theses

In April of 2025, extreme flooding damaged many homes and buildings of people across Kentucky. The Federal Emergency Management Agency (FEMA) produces maps that show the potential for flooding in areas around water bodies, but many of the April flooding damaged areas were well outside of the FEMA classification zones. The main purpose of this thesis research was to create an accurate model of potential flood extent in Kentucky and compare it to FEMA maps. This model did not require extensive computing power and produced a map that accurately depicted flood extent through the use of Digital Elevation Model (DEM) …

The Impact Of State And Federal Policies On Academic Researchers: Findings From A National Survey, Dylan Ruediger, Chelsea Mccracken, Jonathan Barefield

Copyright, Fair Use, Scholarly Communication, etc.

Key findings

● State and federal policies targeting divisive concepts or DEI are shaping research agendas at scale and across disciplines. Twenty percent of all respondents, and 29 percent of researchers working in states with divisive concepts or similar laws, reported having avoided certain research topics because of state laws and policies.

● Eight percent of respondents representing a wide range of disciplines reported having had a federal grant cancelled in 2025.

● Eleven percent of respondents reported that federal and state policies restricting research activities are compelling them to seek employment out of state, to leave the academy, or …

Uptake And Fate Of Silver And Zinc Engineered Nanoparticles In Maize Under Single And Binary Dosing Soil Ecosystems, Lei Xu, Qingbo Yang, Xingmao Ma, Honglan Shi, John Yang, Hu Yang, Samira Mahdi, Ying Wang, Young Shin Jun

Chemistry Faculty Research & Creative Works

Recent agricultural applications of engineered metallic nanoparticles (ENPs) have raised concerns about their uptake and fate in plants. To understand this critical issue, this study investigated the fate and uptake of silver (Ag) and zinc oxide (ZnO) ENPs in maize (Zea mays L.) after single or binary ENP exposure in soil. Results indicated that both Zn and Ag elemental concentrations in roots increased with increasing ENP dosage. Ag NPs in the tissues were detected, but not Zn NPs. Ag NP concentration was 3 times higher in the roots than in the shoots at low Ag NP dosing, while Ag NP …

Impacts Of Climate Change On Agricultural Production And Adaptation Strategies In Northeast China, Ming Jiang, Aizhen Liang, Peng Qi

Bulletin of Chinese Academy of Sciences (Chinese Version)

As the “stabilizer” of national food security, Northeast China is highly sensitive to climate change. Over the past 60 years, the regional temperature has risen significantly at a rate of 0.034℃/a, which is much higher than the global average of 0.0074℃/a. The improvement of thermal resources has driven a significant northward expansion of high-yield and heat-demanding crops, such as maize and rice. Nevertheless, increased warming has enhanced evapotranspiration demand, which, combined with the expansion of planting scales, has led to a 19.8% increase in agricultural irrigation water consumption over the past 20 years, resulting in a prominent contradiction between supply …

Challenges In Strategic Exploitation Of Deep-Sea Minerals And China’S Countermeasures, Chang Wang, Xiaojie Shu, Siyuan Zhou, Huiling Song, Shaojun Liu, Xiangxin Xu, Tao Dai, Tao Zhang, Peng Wang, Zheng Li, Jinhua Cheng

Bulletin of Chinese Academy of Sciences (Chinese Version)

Facing the new stage of strategic mining of deep-sea minerals and the long-term pressure of supply of critical minerals, China urgently needs to seize the window of opportunity for the strategic exploitation of deep-sea critical minerals and open up new sources of supply of critical minerals. Having analyzed the new global situation and challenges of the strategic exploitation of deep-sea critical mineral resources, the study attempted to clarify the supporting role of deep-sea mining in securing critical mineral supply, as well as the actual conditions and main obstacles for the strategic exploitation of deep-sea critical mineral resources in China. Based …

Northern Rainstorm Belt And Response Strategies, Jianping Huang, Xiaodan Guan, Xiaohuang Liu, Xiaohan Shen, Xiaojie Liu

Bulletin of Chinese Academy of Sciences (Chinese Version)

In the summer of 2025, the Northern Rainstorm Belt stretching from eastern Northwest China to the Northeast region exhibited a significant increase in summer precipitation and rainfall frequency over northern China. Cities in the north were frequently struck by extreme rainstorms, resulting in prominent disasters such as “floods in drylands and urban waterlogging”. Northern China spans a vast territory, serving not only as a major grain-producing area and a densely populated region but also as an ecological security barrier that connects the farming-pastoral ecotone and the Loess Plateau. Its stability has nationwide implications. Therefore, comprehensively enhancing flood control capacity, strengthening …

Risks And Challenges Under Approaching Climate Tipping Points And Governance Recommendations, Chengdong Huang, Xiaohong Chen, Zhifang Zhou

Bulletin of Chinese Academy of Sciences (Chinese Version)

Climate tipping points represent critical thresholds at which Earth’s climate subsystems undergo abrupt transitions, characterized by irreversibility, self-perpetuation, and complex interconnections, posing severe challenges to global climate governance. This study systematically elucidates the scientific implications and key features of climate tipping points, with a focus on analyzing the multifaceted risks triggered by their activation, including climatic physical risks, socio-economic systemic risks, and national security risks. To address these challenges, the research proposes a governance framework centered on “preventing abrupt changes—maintaining resilience—actively adapting”, emphasizing pathways such as enhanced monitoring and early warning, cultivating new quality productive forces, and constructing a global …