Autonomous Navigation Trajectory Evaluation Method Based on Uncertainty Analysis

The power transient stability analysis is one of the basis for determining the control strategy of power system security and stability. Considering the influence of power grid topology on the transient stability of power system, the transient stability evaluation model is constructed based on the graph attention neural network. The electrical components and their transient operation data are mapped to the graph data with the spatial topology characteristics of power system for model training, so as to improve the topological generalization performance of the model. The marginal contribution of input characteristics to the output of transient power angle stability evaluation model is quantitatively calculated based on Shapley additive explanation (SHAP), so as to improve the interpretability of data-driven method for transient power angle stability evaluation. The effectiveness of the proposed method is verified by the IEEE 39-bus system.

Aiming at the problems of making fuzziness precise and fixed weight in the fuzzy comprehensive evaluation of lane changing process, a lane change evaluation method based on cloud model and incentive-punishment variable weights was proposed. Based on a driving simulator, the highway driving simulation experiment was conducted to obtain the vehicle's parameters in the lane changing process. Five single index evaluation cloud models of safety, smoothness, comfort, efficiency and ecology in the lane changing process were established. The average membership degree of each index belonging to the four levels of excellent, good, fair and poor was obtained. Considering the subjectivity of experts and the objectivity of data samples, the combination weights were obtained. According to the balance and prominence of the indexes, the combination weights were appropriately rewarded and punished to obtain the final weights. Finally, the evaluation method based on the cloud model and incentive-punishment variable weights was used to evaluate 35 lane change processes, and the proposed method was compared with the method based on the constant weights. There are 32 processes for which the results of the two evaluation methods are the same, while there are 3 processes for which the results of the two evaluation methods are different. Through the further analysis of the indexes, it is found that the evaluation results of incentive-punishment variable weights are more reasonable and accurate.

The cloud model can combine randomicity with ambiguity, and realize the transform between quality and quantity. This paper analyzed the cloud model, focused on the normal cloud and its digital characters, provided a method for evaluating system effectiveness based on cloud model, implementing the transform between qualitative evaluation and quantitative numerical value. Meanwhile the evaluating target system of airborne EW system be constructed and applied this method to evaluate EW system.

It is necessary to carry out an integrated connection design for the rail station area to promote the development of the transit-oriented development (TOD) mode. There is lack of an evaluation index system that comprehensively considers the characteristics of TOD. Based on the characteristics of TOD mode and passenger transfer satisfaction, we propose an evaluation index system for the design of the connections between TOD rail stations and each of the three transportation modes including pedestrians, conventional buses and non-motorized vehicles, respectively. We formulate the grading standards for quantitative and qualitative indicators through literature research and questionnaire survey, respectively. In order to obtain relatively objective and comprehensive evaluation results, we propose an evaluation method combining analytic hierarchy process (AHP) and cloud model, which is superior to single evaluation methods. Finally, Nanjing Xinjiekou rail station is selected as a case for the application of indexes and the evaluation method. The evaluation results about the connection levels of the three transportation modes are medium, good, and medium, which basically conform to the characteristics of central commercial stations.

With Innovative capital perspective, the proportion of R & D personnel, R & D intensity, R & D productivity and per capita number of patents are constructed as the industry's innovation capacity evaluation indexes. Using cloud theoretical framework, the evaluation method of industry's innovation capacity based on cloud model is built. Through the backward cloud algorithm, this method combines qualitative and quantitative evaluation for the average level of innovation capability, the degree of difference and the stability. In accordance with cloud diagrams generated by forward cloud algorithm being reflected in the simulation of innovation capability, a more intuitive way for decision-makers describes innovation capacity. Then, the model validation and simulation results with the sample of 170 listed companies in the manufacturing sector data in 2004, reflects the lack of innovative capacity of China's manufacturing industry and showed unstable situation. According to cloud theory, this instability comes from policy, market, knowledge networks, and other environmental factors, and thereby it gives some policy recommendations to enhance industry innovation capacity.

As a highly practical technique, grouting repair technology is widely used in the practical repair of highway diseases. Existing single indicator detection methods can well reflect certain characteristic indicators of roads, such as compaction and strength. However, the road performance after grouting often needs to be comprehensively evaluated from multiple perspectives, which is difficult to achieve through a single detection method. Therefore, this paper proposes a multi-index evaluation method that comprehensively considers the mechanical properties, uniformity, and compactness of the road after grouting repair. This method combines hierarchical analysis and entropy weight method, integrating subjective evaluation with objective reality, to assign weights to each evaluation index and obtain the weight ranking of relevant influencing factors in the evaluation index system. Based on these index and the combined assign weight method, a comprehensive evaluation model for asphalt pavement is constructed and demonstrated by cloud model step by step. Taking the reconstruction and expansion project of an actual expressway as an example, the grouting effect is evaluated by the proposed model. After that, the actual excavation situation of the expressway show that the evaluation results are closer to the actual performance. The transition from qualitative and empirical evaluation of grouting repair effect to scientific and semi-quantitative evaluation has been initially achieved. The evaluation model for grouting effect based on the combined weighting method-cloud model can accurately, and effectively evaluate the performance of the expressway after grouting repair. Received: 9.5.2024 Received in revised form: 25.7.2025 Accepted: 30.8.2025

A novel multilevel decision-making evaluation approach for the renewable energy heating systems: A case study in China

With the development of science and technology, the cost of offshore wind power development and transmission has gradually decreased, making offshore wind power technology a research hotspot. The installed capacity has been increasing year by year. China has abundant offshore wind energy resources, which are much richer than those on land and are available for exploitation. Offshore wind speeds are stable and do not produce harmful substances. Therefore, studying the transient voltage stability of offshore wind power grid-connected systems to improve the utilization efficiency of offshore wind power and protect the ecological environment is critical. After large-scale wind power is connected to the grid, ensuring the stability of the system's transient voltage becomes crucial. This paper aims to deeply study the transient voltage stability of offshore wind farm grid-connected systems, providing theoretical support for the subsequent design and operation of offshore wind farms. A simulation model of a typical power system integrated with offshore wind farms was established using PSAT. Relevant transient voltage stability indices were calculated, and the impact of varying wind speeds on the transient voltage stability of the grid-connected system was investigated. Static Var Compensators (SVC) and Static Synchronous Compensators (STATCOM) were installed for comparative analysis. The results demonstrate that excessively low wind speeds degrade the system's transient stability, and the installation of SVC provides superior improvement in transient voltage stability compared to STATCOM.

People pay more attention to analyzing the sports problems with mathematical methods. The paper takes the technical statistical data and game performance of NBA basketball players in 2021-2022 season as the research object, selects indexes by literature review, questionnaire and mathematical statistics, and conducts research on the technical ability, tactical awareness, fitness level and game performance of NBA basketball players. Based on statistical mathematics and fuzzy mathematics, the paper introduces the concept of index contribution rate, and constructs comprehensive evaluation model of competitive ability of outstanding basketball players with improved order relation method and cloud model, making both quantifiable indexes and non-quantifiable factors involved in the evaluation process. First of all, it uses improved order relation method to determine index weight, and constructs the index weight evaluation model of basketball players’ comprehensive ability. Secondly, with NBA players’ data as sample data, it realizes the conversion between qualitative concept and quantitative concept based on cloud model algorithm, uses Matlab to conduct simulation analysis to derive the order relation weight table, compares and analyzes the evaluation cloud chart and standard cloud chart based on cloud model, and analyzes the weight and influence of each index in the players’ comprehensive ability evaluation to determine the preferred index. Finally, the author verifies the indexes selected by mathematical method and the indexes of 503 basketball players published on the NBA official website in 2022-2023 season, proving that it is effective and can achieve the unity of subjective and objective. This demonstrates that the basketball players’ comprehensive ability evaluation system built in this paper is reasonable and has reference significance for basketball players and coaches. Compared with other weight evaluation models, the comprehensive ability index system established by the evaluation method provides a systematic method for quantitative analysis and comprehensive evaluation of basketball players’ competitive ability, and has practical significance for improve basketball players’ competitive performance with mathematical model.

Patent risk evaluation is the premise of patent risk control for R&D alliance and it plays an important role in reducing risks and improving patent output. From the five aspects of patent technology risk, patent right risk, patent implementation risk, cooperation risk and environmental risk, the patent risk evaluation index was designed and then its evaluation method based on cloud model was constructed. After that, an empirical analysis of X alliance was made which showed that this method could not only assess the patent risk level but also find the major influencing factors. This research may provide support for R&D alliance to scientifically identify the patent risk factors and accurately grasp the patent risk level so as to take effective measures to prevent risks and reduce the loss.

Comprehensive evaluation of voltage stability based on EW-AHP and Fuzzy-TOPSIS

This article investigates the phase-locked loop (PLL) synchronization transient stability (PLL-STS) issue of grid-tied multiple voltage source converters (MVSCs) systems, specifically focusing on transient stability evaluation and transient interaction analysis. First, a novel PLL-STS assessment method for MVSCs systems has been proposed, which considers angular frequency jumps, nonlinear damping, and transient interactions among VSCs. Compared with previous studies, this method can accurately evaluate PLL-STS of MVSCs system since the acceleration and deceleration areas of VSCs can be accurately determined by combining equal-area criterion and numerical integration method. Moreover, it can identify the dominant converters which lead to transient instability. Second, by introducing static and dynamic interaction coefficients, influence of static and dynamic interaction on the transient stability of individual converters is quantitatively analyzed. Finally, the theoretical analysis results are verified by PSCAD/ EMTDC time-domain simulation results and RT-LAB hardware-in-the-loop experimental results.

FMEA-CM based quantitative risk assessment for process industries—A case study of coal-to-methanol plant in China

Stability of wind power is the long-concerned issue especially in the context of high grid-integration level. Different from traditional synchronous generators, the transient synchronization stability of the wind turbine is maintained by the phase-locked loop after being disturbed. This paper mainly discusses the transient stability of the doubly-fed wind turbine. Firstly, according to the principle of doubly-fed wind turbines connected to grid, a doubly-fed wind turbine model under the time scale of transient stability analysis is established. Then, by theoretically analyzing the dynamic process after being disturbed, the acceleration and deceleration area of phase-locked loop analogous to the synchronous generator is proposed. The critical stability region of the system is analyzed, and a calculation method for the transient synchronization stability margin of doubly-fed wind turbines is proposed. Finally, a detailed model of four-machine two-zone system is built on MATLAB/Simulink software, and the correctness of the conclusion is verified by analyzing the influence of key parameters on transient stability.

Based on the fuzziness and randomness of cloud model, it is applied to the construction safety risk assessment of long-span suspension bridge in deep valley in mountainous area. According to the situation of Jiangdi River Bridge project, the cloud model evaluation method is adopted to add two indexes of wind load condition and import and export construction condition to the index system. The index weight is calculated by the maximum deviation weighting method, the comprehensive determination degree is calculated and the construction safety risk level is determined. By comparing the standard evaluation results of construction Safety Risk Assessment Guide for Highway Bridges and Tunnels (Trial) and the cloud model evaluation results, it is shown that the evaluation index system is constituted by adding corresponding special risk factors to the actual project and cloud model calculation is more reasonable and accurate than the traditional risk evaluation results.