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A Decision-Making Framework Model of Cutting Fluid Selection for Green Manufacturing and the Case Study 被引量:5
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作者 TAN Xian-chun 1, LIU Fei 1, CAO Hua-jun 1, ZHANG Hua 2 (1. The Institute of Manufacturing Engineering, Chongqing University, Chongqing 400044, China 2. School of Manufacturing & Automation, Wuhan University of Science & Technol ogy, Wuhan 430081, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期136-137,共2页
Pursuing the green manufacturing (GM) of products i s very beneficial in the alleviation of environment burdens. In order to reap such benefits, green manufacturing is involved in every aspect of manufacturing proc es... Pursuing the green manufacturing (GM) of products i s very beneficial in the alleviation of environment burdens. In order to reap such benefits, green manufacturing is involved in every aspect of manufacturing proc esses. During the machining process, cutting fluid is one of the main roots of e nvironmental pollution. And how to make an optimal selection for cutting fluid f or GM is an important path to reduce the environmental pollution. The objective factors of decision-making problems in the traditional selection of cutting flu id are usually two: quality and cost. But from the viewpoint of GM, environmenta l impact (E) should be considered together. In this paper, a multi-object d ecision-making model of cutting fluid selection for GM is put forward, in which the objects of Quality (Q), Cost(C) and Environmental impact (E) are considered together. In this model, E means to minimize the environmental impact, Q means to maximize the quality and C means to minimize the cost. Each objective is anal yzed in detail too. A case study on a decision-making problem of cutting fluid selection in a gear hobbing process is analyzed, and the result shows the model is practical. 展开更多
关键词 green manufacturing cutting fluid decision-mak ing model environmental impact
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Ranking environmental projects model based on multicriteria decision-making and the weight sensitivity analysis 被引量:5
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作者 Jiang Yan Tian Dagang Pan Yue 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2007年第3期534-539,共6页
With the fast growth of Chinese economic, more and more capital will be invested in environmental projects. How to select the environmental investment projects (alternatives) for obtaining the best environmental qua... With the fast growth of Chinese economic, more and more capital will be invested in environmental projects. How to select the environmental investment projects (alternatives) for obtaining the best environmental quality and economic benefits is an important problem for the decision makers. The purpose of this paper is to develop a decision-making model to rank a finite number of alternatives with several and sometimes conflicting criteria. A model for ranking the projects of municipal sewage treatment plants is proposed by using exports' information and the data of the real projects. And, the ranking result is given based on the PROMETHEE method. Furthermore, by means of the concept of the weight stability intervals (WSI), the sensitivity of the ranking results to the size of criteria values and the change of weights value of criteria are discussed. The result shows that some criteria, such as “proportion of benefit to project cost”, will influence the ranking result of alternatives very strong while others not. The influence are not only from the value of criterion but also from the changing the weight of criterion. So, some criteria such as “proportion of benefit to project cost” are key critera for ranking the projects. Decision makers must be cautious to them. 展开更多
关键词 multicriteria decision-making ranking environmental projects model PROMETHEE method sensitivity analysis weight stability intervals.
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Consensus model of social network group decision-making based on trust relationship among experts and expert reliability 被引量:2
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作者 WANG Ya CAI Mei JIAN Xinglian 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第6期1576-1588,共13页
Due to people’s increasing dependence on social networks,it is essential to develop a consensus model considering not only their own factors but also the interaction between people.Both external trust relationship am... Due to people’s increasing dependence on social networks,it is essential to develop a consensus model considering not only their own factors but also the interaction between people.Both external trust relationship among experts and the internal reliability of experts are important factors in decision-making.This paper focuses on improving the scientificity and effectiveness of decision-making and presents a consensus model combining trust relationship among experts and expert reliability in social network group decision-making(SN-GDM).A concept named matching degree is proposed to measure expert reliability.Meanwhile,linguistic information is applied to manage the imprecise and vague information.Matching degree is expressed by a 2-tuple linguistic model,and experts’preferences are measured by a probabilistic linguistic term set(PLTS).Subsequently,a hybrid weight is explored to weigh experts’importance in a group.Then a consensus measure is introduced and a feedback mechanism is developed to produce some personalized recommendations with higher group consensus.Finally,a comparative example is provided to prove the scientificity and effectiveness of the proposed consensus model. 展开更多
关键词 social network group decision-making(SN-GDM) trust relationship expert reliability consensus model probabilistic linguistic term set(PLTS).
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Research on the self-defence electronic jamming decision-making based on the discrete dynamic Bayesian network 被引量:6
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作者 Tang Zheng Gao Xiaoguang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2008年第4期702-708,共7页
The manner and conditions of running the decision-making system with self-defense electronic jamming are given. After proposing the scenario of applying discrete dynamic Bayesian network to the decision making with se... The manner and conditions of running the decision-making system with self-defense electronic jamming are given. After proposing the scenario of applying discrete dynamic Bayesian network to the decision making with self-defense electronic jamming, a decision-making model with self-defense electronic jamming based on the discrete dynamic Bayesian network is established. Then jamming decision inferences by the aid of the algorithm of discrete dynamic Bayesian network are carried on. The simulating result shows that this method is able to synthesize different targets which are not predominant. In this way, various features at the same time, as well as the same feature appearing at different time complement mutually; in addition, the accuracy and reliability of electronic jamming decision making are enhanced significantly. 展开更多
关键词 self-defense electronic jamming discrete dynamic Bayesian network decision-making model
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Support vector machine based nonlinear model multi-step-ahead optimizing predictive control 被引量:9
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作者 钟伟民 皮道映 孙优贤 《Journal of Central South University of Technology》 EI 2005年第5期591-595,共5页
A support vector machine with guadratic polynomial kernel function based nonlinear model multi-step-ahead optimizing predictive controller was presented. A support vector machine based predictive model was established... A support vector machine with guadratic polynomial kernel function based nonlinear model multi-step-ahead optimizing predictive controller was presented. A support vector machine based predictive model was established by black-box identification. And a quadratic objective function with receding horizon was selected to obtain the controller output. By solving a nonlinear optimization problem with equality constraint of model output and boundary constraint of controller output using Nelder-Mead simplex direct search method, a sub-optimal control law was achieved in feature space. The effect of the controller was demonstrated on a recognized benchmark problem and a continuous-stirred tank reactor. The simulation results show that the multi-step-ahead predictive controller can be well applied to nonlinear system, with better performance in following reference trajectory and disturbance-rejection. 展开更多
关键词 nonlinear model predictive control support vector machine nonlinear system identification kernel function nonlinear optimization
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Robustly stable model predictive control based on parallel support vector machines with linear kernel 被引量:4
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作者 包哲静 钟伟民 +1 位作者 皮道映 孙优贤 《Journal of Central South University of Technology》 EI 2007年第5期701-707,共7页
Robustly stable multi-step-ahead model predictive control (MPC) based on parallel support vector machines (SVMs) with linear kernel was proposed. First, an analytical solution of optimal control laws of parallel SVMs ... Robustly stable multi-step-ahead model predictive control (MPC) based on parallel support vector machines (SVMs) with linear kernel was proposed. First, an analytical solution of optimal control laws of parallel SVMs based MPC was derived, and then the necessary and sufficient stability condition for MPC closed loop was given according to SVM model, and finally a method of judging the discrepancy between SVM model and the actual plant was presented, and consequently the constraint sets, which can guarantee that the stability condition is still robust for model/plant mismatch within some given bounds, were obtained by applying small-gain theorem. Simulation experiments show the proposed stability condition and robust constraint sets can provide a convenient way of adjusting controller parameters to ensure a closed-loop with larger stable margin. 展开更多
关键词 parallel support vector machines model predictive control stability ROBUSTNESS
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Support Vector Machine-Based Nonlinear System Modeling and Control 被引量:1
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作者 张浩然 韩正之 +1 位作者 冯瑞 于志强 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第3期53-58,共6页
This paper provides an introduction to a support vector machine, a new kernel-based technique introduced in statistical learning theory and structural risk minimization, then presents a modeling-control framework base... This paper provides an introduction to a support vector machine, a new kernel-based technique introduced in statistical learning theory and structural risk minimization, then presents a modeling-control framework based on SVM. At last a numerical experiment is taken to demonstrate the proposed approach's correctness and effectiveness. 展开更多
关键词 support vector machine Statistical learning theory Nonlinear systems modeling and control.
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Bearing mechanism of roof and rib support structure in automatically formed roadway and its support design method 被引量:2
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作者 JIANG Bei WANG Ming-zi +4 位作者 WANG Qi XIN Zhong-xin XING Xue-yang DENG Yu-song YAO Liang-di 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2467-2487,共21页
Non-pillar mining technology with automatically formed roadway is a new mining method without coal pillar reservation and roadway excavation.The stability control of automatically formed roadway is the key to the succ... Non-pillar mining technology with automatically formed roadway is a new mining method without coal pillar reservation and roadway excavation.The stability control of automatically formed roadway is the key to the successful application of the new method.In order to realize the stability control of the roadway surrounding rock,the mechanical model of the roof and rib support structure is established,and the influence mechanism of the automatically formed roadway parameters on the compound force is revealed.On this basis,the roof and rib support structure technology of confined lightweight concrete is proposed,and its mechanical tests under different eccentricity are carried out.The results show that the bearing capacity of confined lightweight concrete specimens is basically the same as that of ordinary confined concrete specimens.The bearing capacity of confined lightweight concrete specimens under different eccentricities is 1.95 times higher than those of U-shaped steel specimens.By comparing the test results with the theoretical calculated results of the confined concrete,the calculation method of the bearing capacity for the confined lightweight concrete structure is selected.The design method of confined lightweight concrete support structure is established,and is successfully applied in the extra-large mine,Ningtiaota Coal Mine,China. 展开更多
关键词 automatically roadway with non-pillar confined lightweight concrete roof and rib support mechanical model bearing behaviour
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Artificial Intelligence Based Meteorological Parameter Forecasting for Optimizing Response of Nuclear Emergency Decision Support System
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作者 BILAL Ahmed Khan HASEEB ur Rehman +5 位作者 QAISAR Nadeem MUHAMMAD Ahmad Naveed Qureshi JAWARIA Ahad MUHAMMAD Naveed Akhtar AMJAD Farooq MASROOR Ahmad 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第10期2068-2076,共9页
This paper presents a novel artificial intelligence (AI) based approach to predict crucial meteorological parameters such as temperature,pressure,and wind speed,typically calculated from computationally intensive weat... This paper presents a novel artificial intelligence (AI) based approach to predict crucial meteorological parameters such as temperature,pressure,and wind speed,typically calculated from computationally intensive weather research and forecasting (WRF) model.Accurate meteorological data is indispensable for simulating the release of radioactive effluents,especially in dispersion modeling for nuclear emergency decision support systems.Simulation of meteorological conditions during nuclear emergencies using the conventional WRF model is very complex and time-consuming.Therefore,a new artificial neural network (ANN) based technique was proposed as a viable alternative for meteorological prediction.A multi-input multi-output neural network was trained using historical site-specific meteorological data to forecast the meteorological parameters.Comprehensive evaluation of this technique was conducted to test its performance in forecasting various parameters including atmospheric pressure,temperature,and wind speed components in both East-West and North-South directions.The performance of developed network was evaluated on an unknown dataset,and acquired results are within the acceptable range for all meteorological parameters.Results show that ANNs possess the capability to forecast meteorological parameters,such as temperature and pressure,at multiple spatial locations within a grid with high accuracy,utilizing input data from a single station.However,accuracy is slightly compromised when predicting wind speed components.Root mean square error (RMSE) was utilized to report the accuracy of predicted results,with values of 1.453℃for temperature,77 Pa for predicted pressure,1.058 m/s for the wind speed of U-component and 0.959 m/s for the wind speed of V-component.In conclusion,this approach offers a precise,efficient,and wellinformed method for administrative decision-making during nuclear emergencies. 展开更多
关键词 prediction of meteorological parameters weather research and forecasting model artificial neural networks nuclear emergency support system
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Integrating Knowledge-Based Simulation with Aspiration-Directed Model-based Decision Support System
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作者 Feng Shan & Li D. Xu(Department of Automatic Control Engineering,Huazhong University of Science and Technology Wuhan, Hubei 430074, China)(Department of Management Science and Information systems Wright State University, Dayton, OH 45435, USA) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1996年第2期25-33,共9页
This paper reports an aspiration-directed, model-based decision support system (AMDSS) integrated with a knowledge-based simulation system. The system is designed to study China's mid-range economic development st... This paper reports an aspiration-directed, model-based decision support system (AMDSS) integrated with a knowledge-based simulation system. The system is designed to study China's mid-range economic development strategy. The capacity of the system is enhanced by the knowledge-based component which provides a knowledge-based simulation environment for model management. Currently the system has passed the stage of prototype and achieves its implementation capacity. The paper first presents the mathematical aspects of decision making including aspiration-directed decision making, then discusses the architecture of the system. The purpose of the paper is to provide insights into how such an integrated system could provide decision support for complex decision analysis. 展开更多
关键词 Knowledge-based simulation model-based reasoning Decision support system
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考虑中间主应力和支护力的巷道围岩黏-弹塑性解 被引量:1
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作者 经来旺 冯瑜腾 +3 位作者 郑霖 谢金鑫 黄旭 经纬 《中国矿业》 北大核心 2025年第1期146-153,共8页
岩石流变特性对巷道围岩的变形具有重要影响,往往会导致围岩发生大变形甚至失稳。为了全面地分析圆形巷道围岩的变形特性,采用流变模型的串联理论,将Burgers模型与统一强度准则下的摩擦片进行组合,得到了一种考虑围岩塑性的黏-弹塑性围... 岩石流变特性对巷道围岩的变形具有重要影响,往往会导致围岩发生大变形甚至失稳。为了全面地分析圆形巷道围岩的变形特性,采用流变模型的串联理论,将Burgers模型与统一强度准则下的摩擦片进行组合,得到了一种考虑围岩塑性的黏-弹塑性围岩本构模型。在对围岩进行弹塑性分析时,考虑了中间主应力系数和支护力的影响,并利用非关联流动法则,得到了巷道围岩塑性区半径和位移解析式。结合算例分析了中间主应力和支护力对巷道围岩塑性区半径及其应力场和位移场的影响,以及位移随时间的变化规律。研究结果表明:巷道围岩先后经历减速蠕变和稳速蠕变两个阶段。在减速阶段,围岩的位移增速较大,前期支护压力大。而在稳速阶段,围岩位移增速虽略有减小,但依然需要支护保持稳定;通过增大中间主应力和支护力,可以减小塑性区半径和围岩位移,提高巷道围岩的稳定性。此外,随着时间的增加,围岩变形逐渐增大,而通过增大支护力,可有效抑制围岩发生变形的速度,在一定程度上缓解了围岩变形。 展开更多
关键词 岩石流变特性 黏-弹塑性模型 蠕变 统一强度准则 BURGERS模型 支护力
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基于机器学习的30%TBP/煤油-硝酸体系中主要组分的分配比预测研究 被引量:1
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作者 于婷 张音音 +6 位作者 张睿志 金文蕾 罗应婷 朱升峰 何辉 叶国安 龚禾林 《原子能科学技术》 北大核心 2025年第1期14-23,共10页
为最优化后处理过程的实验条件、优化工艺、降低实验成本和时间,并提高后处理流程数学模拟的准确性,本文基于随机森林、支持向量回归和K近邻这3种经典的机器学习算法建立了30%TBP/煤油-硝酸体系中主要组分铀、钚、硝酸的分配比数学模型... 为最优化后处理过程的实验条件、优化工艺、降低实验成本和时间,并提高后处理流程数学模拟的准确性,本文基于随机森林、支持向量回归和K近邻这3种经典的机器学习算法建立了30%TBP/煤油-硝酸体系中主要组分铀、钚、硝酸的分配比数学模型,并基于不同数据集进行了超参数优化和模型训练。通过对模型进行验证和测试,发现采用随机森林算法建立的分配比模型准确度最高,其对铀预测的平均绝对相对误差达7.73%,较传统方法提高了约7%。与传统建模方法相比,机器学习方法建立模型的准确度更高。 展开更多
关键词 分配比数学模型 随机森林 支持向量回归 K近邻
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伺服钢支撑控制旁侧既有盾构隧道变形试验研究 被引量:1
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作者 王哲 吴鹏飞 +5 位作者 魏纲 冯韦皓 吴雪桦 李航 易子浩 胡恬华 《铁道科学与工程学报》 北大核心 2025年第2期795-806,共12页
为探明伺服钢支撑主动控制旁侧既有盾构隧道变形时基坑和隧道的整体受力变形规律和机理,解决工程中伺服钢支撑的不合理应用问题,开展室内缩尺模型试验,通过分析地连墙变形、隧道变形、隧道围压与内力、周围土压力等试验数据,以及伺服钢... 为探明伺服钢支撑主动控制旁侧既有盾构隧道变形时基坑和隧道的整体受力变形规律和机理,解决工程中伺服钢支撑的不合理应用问题,开展室内缩尺模型试验,通过分析地连墙变形、隧道变形、隧道围压与内力、周围土压力等试验数据,以及伺服钢支撑不同组合方式下的隧道变形控制效果,研究伺服钢支撑主动控制旁侧隧道变形的规律和机理。试验结果表明:伺服加载对隧道水平位移和拱顶沉降均有一定的控制效果,且对水平位移的控制效果更加显著,对隧道右拱腰围压与弯矩的影响最大,拱顶拱底次之,对左拱腰影响最小,对地表沉降未产生显著的控制效果。伺服加载在旁侧土体产生的附加应力,随着距离增大产生消散现象,在隧道右拱腰产生应力集中现象,伺服加载对地连墙变形、隧道围压和弯矩、隧道变形的影响同步产生且相互关联。伺服钢支撑设置位置越靠近隧道埋深处、设置层数越多对隧道变形控制效果越好,但设置位置不当时设置层数与隧道变形控制效果不成正比,甚至产生负向控制效果,工程中应重点考虑伺服钢支撑的设置位置,不可盲目增大设置层数,否则增加工程成本且可能产生工程风险。研究结果可为伺服钢支撑主动控制围护结构及旁侧隧道变形提供理论指导,利于其更加广泛而合理地应用。 展开更多
关键词 盾构隧道 深基坑 伺服钢支撑 地连墙变形 模型试验
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基于扩展D-P的粮食筒仓地震作用下动态侧压力影响参数研究
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作者 许启铿 张振乾 +2 位作者 刘强 王丽坤 李亮 《振动与冲击》 北大核心 2025年第6期213-222,共10页
地震作用下,筒仓结构与粮食颗粒的动力相互作用引起的动态超压是筒仓结构安全的重要问题。为此,基于扩展的D-P(Drucker-Prager)模型的颗粒本构,建立了柱承式筒仓-粮食颗粒有限元模型,并结合开展的振动台试验对动态侧压力进行对比分析和... 地震作用下,筒仓结构与粮食颗粒的动力相互作用引起的动态超压是筒仓结构安全的重要问题。为此,基于扩展的D-P(Drucker-Prager)模型的颗粒本构,建立了柱承式筒仓-粮食颗粒有限元模型,并结合开展的振动台试验对动态侧压力进行对比分析和验证,进一步构建实仓有限元模型,研究多种粮食参数对动态侧压力的影响规律,并进行了灰色关联分析。结果表明:基于扩展D-P模型的有限元模型能够反映筒仓粮食动态侧压力的变化趋势,验证了有限元模型的合理性;摩擦因数对动态侧压力的影响与所处高度相关;弹性模量对动态侧压力的关联度最大;研究揭示了地震作用下粮食参数对动态侧压力的影响机理及参数影响关联性,为筒仓-粮食颗粒动力问题数值模拟地参数选取提供了借鉴,也为筒仓结构抗震设计提供参考。 展开更多
关键词 筒仓 有限元模型 粮食颗粒 DRUCKER-PRAGER模型 动态侧压力
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土地制度综合配套改革对城乡收入差距的影响
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作者 丰雷 李聪 《中国土地科学》 北大核心 2025年第1期50-59,共10页
研究目的:考察土地制度综合配套改革对缩小城乡收入差距的政策效果,为实现更加公平合理的土地收益分配提出政策建议。研究方法:理论建模、固定效应模型。研究结果:(1)土地制度综合配套改革对缩小城乡收入差距具有显著影响,土地制度综合... 研究目的:考察土地制度综合配套改革对缩小城乡收入差距的政策效果,为实现更加公平合理的土地收益分配提出政策建议。研究方法:理论建模、固定效应模型。研究结果:(1)土地制度综合配套改革对缩小城乡收入差距具有显著影响,土地制度综合改革的政策配套度越高,越有利于城乡收入差距的缩小。(2)土地制度综合配套改革主要包括政策主体配套以及政策工具配套两种形式,这两种形式的配套度提高,都能显著缩小城乡收入差距。(3)土地制度综合配套改革的政策效应具有区域异质性,对东、中部地区城乡收入差距的缩小效应比西部地区更大。研究结论:进一步完善政策主体配套以及政策工具配套,整合土地、劳动力、社保以及资金等要素配套,有助于促进土地增值收益的全民共享,缩小城乡收入分配差距。 展开更多
关键词 土地制度综合配套改革 政策主体配套 政策工具配套 城乡收入差距 固定效应模型
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可控刚度支承结构动力学特性实验研究
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作者 龚存忠 王贵龙 +2 位作者 国阳 徐科繁 张广辉 《汽轮机技术》 北大核心 2025年第4期284-288,298,共6页
为研究支承结构的刚度特性及其对转子系统动力学性能的影响,设计并搭建了可控刚度支承结构试验台。针对某船用汽轮给水机组转子,利用有限元方法建立其模化转子模型,依次开展了模化转子临界转速及模态振型仿真、支承刚度敏感性仿真、不... 为研究支承结构的刚度特性及其对转子系统动力学性能的影响,设计并搭建了可控刚度支承结构试验台。针对某船用汽轮给水机组转子,利用有限元方法建立其模化转子模型,依次开展了模化转子临界转速及模态振型仿真、支承刚度敏感性仿真、不平衡响应试验等。研究结果表明:可控刚度支承结构有效调节了转子临界转速,减少了转子振动峰值;通过调整鼠笼和金属橡胶环的刚度范围,实现了对转子不平衡响应的显著减振效果,减振效果达到39.22%。该研究为舰船动力装置转子系统的减振优化设计提供了可靠的理论依据和工程参考。 展开更多
关键词 可控刚度支承结构 模化转子 刚度调节 临界转速 不平衡响应 减振效果
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子女社会经济地位对老年父母心理健康的影响——“面子”效应还是“里子”效应
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作者 陈佳鞠 赵若彤 李龙 《人口学刊》 北大核心 2025年第3期65-80,共16页
老年人是精神较脆弱的群体,抑郁是老年人常见的心理健康问题之一。社会经济地位作为一种代际资源可以产生跨代影响,既有研究已经发现子女的社会经济地位对老年父母的心理健康有积极的影响,但对子女的社会经济地位通过什么机制影响老年... 老年人是精神较脆弱的群体,抑郁是老年人常见的心理健康问题之一。社会经济地位作为一种代际资源可以产生跨代影响,既有研究已经发现子女的社会经济地位对老年父母的心理健康有积极的影响,但对子女的社会经济地位通过什么机制影响老年父母的抑郁症状这一问题的认识仍不够清晰。本文基于2020年中国老年社会追踪调查(CLASS)数据,利用结构方程模型探讨子女社会经济地位对老年父母抑郁症状的影响机制,重点关注子女经济支持和老年父母朋友交际的中介作用,并从子女社会经济地位蕴含的物质性资源(“里子”效应)和符号性资源(“面子”效应)视角进行了城乡分组分析,旨在厘清和比较两种影响机制。研究发现:子女较高的社会经济地位通过更多的经济支持以及扩大老年父母的朋友交际网络抑制老年父母的抑郁症状,子女经济支持的中介作用大于老年父母朋友交际的中介作用,老年父母从子女较高社会经济地位蕴含的物质性资源和符号性资源中分别收获了“里子”和“面子”,同时,物质性资源还可以通过符号性资源对老年父母的生活福祉、心理健康产生影响,即存在“面子”效应和“里子”效应,“里子”效应大于“面子”效应,且“里子”效应可以通过“面子”效应发挥作用。城乡分组分析的结果表明:在农村老年人中,子女较高的社会经济地位通过扩大老年父母的朋友交际网络抑制老年父母的抑郁症状,子女经济支持也要通过影响老年父母的朋友交际发挥作用,即中国农村社会依然存在重“面子”的现象,“里子”效应需要通过“面子”效应来发挥作用;在城镇老年人中,子女较高的社会经济地位通过更多的经济支持抑制老年父母的抑郁症状,而老年父母朋友交际的中介作用不显著,即在中国城镇老年人中,“面子”效应不明显,而纯粹的“里子”效应更明显,城镇老年人更关注物质生活的质量。本文建议应通过多渠道为老年人提供改善心理健康状况的资源,推进青年群体的教育和就业支持体系建设,完善社会保障体系以及加强新时代文明建设。 展开更多
关键词 社会经济地位 抑郁症状 结构方程模型 代际支持 城乡差异
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基于DWT-CNN-Informer模型的液压支架压力多步长预测
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作者 张传伟 张刚强 +1 位作者 路正雄 李林岳 《中国安全生产科学技术》 北大核心 2025年第4期57-63,共7页
为了实现液压支架压力多步长精准预测,提出1种基于DWT-CNN-Informer模型的压力多步长预测方法,该方法利用离散小波变换(discrete wavelet transform, DWT)将预处理后的压力时序数据分解为趋势项和周期项频率分量;各频率分量输入卷积神... 为了实现液压支架压力多步长精准预测,提出1种基于DWT-CNN-Informer模型的压力多步长预测方法,该方法利用离散小波变换(discrete wavelet transform, DWT)将预处理后的压力时序数据分解为趋势项和周期项频率分量;各频率分量输入卷积神经网络(CNN)模型提取频率特征;提取的频率特征输入Informer编码器,经位置编码和多头概率稀疏自注意力机制捕捉时序变化特征,并结合自注意力蒸馏减少特征冗余;将Informer解码器改为全连接层,直接输出各分量多步长预测结果;重构叠加各分量多步长预测结果得到液压支架压力多步长预测结果。研究结果表明:在预测步长分别为6,12,24时,DWT-CNN-Informer模型相比LSTM、Informer、CNN-Informer模型在平均绝对误差(MAE)、均方根误差(RMSE)、对称平均绝对百分比误差(SMAPE)指标上均表现出更高预测精度。研究结果为液压支架压力精准预测提供有效方法。 展开更多
关键词 液压支架压力 多步长预测 离散小波变换 CNN模型 Informer模型
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论“掘进就是掘模型”的学术思想
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作者 马宏伟 孙思雅 +16 位作者 王川伟 毛清华 薛旭升 刘鹏 田海波 王鹏 张烨 聂珍 马柯翔 郭逸风 张恒 王赛赛 李烺 苏浩 崔闻达 成佳帅 喻祖坤 《煤炭学报》 北大核心 2025年第1期661-675,共15页
为了实现煤矿巷道安全、高效、智能掘进,提出了“掘进就是掘模型”的学术思想,给出了“掘进就是掘模型”学术思想的内涵和体系架构,凝练了“掘进就是掘模型”的关键技术问题,即融合多源信息的多元巷道模型构建技术、基于巷道模型的智能... 为了实现煤矿巷道安全、高效、智能掘进,提出了“掘进就是掘模型”的学术思想,给出了“掘进就是掘模型”学术思想的内涵和体系架构,凝练了“掘进就是掘模型”的关键技术问题,即融合多源信息的多元巷道模型构建技术、基于巷道模型的智能截割技术、基于巷道模型的智能临时支护技术、基于巷道模型的智能永久支护技术、基于巷道模型的智能导航技术和基于巷道模型的机群智能并行协同控制技术。针对巷道模型构建问题,提出融合地质勘探、巷道设计、超前探测等多源数据的巷道模型构建方法,为掘进系统各子系统模型构建提供统一基准;针对基于巷道模型的智能截割问题,建立了待掘巷道模型与截割子系统模型的耦合子模型,提出了智能截割轨迹规划以及截割参数优化方法,制定了巷道智能截割策略,实现了截割子系统自适应规划截割;针对基于巷道模型的智能临时支护问题,建立了截割巷道模型与临时支护子系统耦合的临时支护子模型,提出了临时支护位姿与支护力自适应调整方法,实现了临时支护子系统安全可靠作业,提高了围岩的稳定性,为掘锚并行协同作业奠定了时空基础;针对基于巷道模型的永久支护问题,建立了临时支护巷道模型与永久支护子系统耦合的永久支护子模型,提出了受限时空下永久支护子系统内部各钻锚设备的协同控制方法,实现了永久支护子系统的高效协同控制;针对基于巷道模型的智能导航问题,建立了巷道模型与导航子系统耦合的导航子模型,提出了“惯导+全站仪”的智能掘进系统精确导航方法,提高了巷道掘进精度和成型质量;针对基于巷道模型的机群智能并行协同控制问题,建立了巷道模型与机群协同控制子系统耦合的并行协同控制子模型,制定了多机并行协同控制策略,提出了多任务多系统智能掘进系统协同控制方法,实现了智能掘进系统安全高效掘进。基于“掘进就是掘模型”的学术思想,研发了护盾式煤矿巷道掘进机器人系统,成功应用于陕煤化集团陕西小保当矿业有限公司,破解了夹矸厚、硬度大、片帮严重等复杂地质条件煤矿巷道掘进难题,有效提高了巷道掘进的安全性、高效性和智能化水平。 展开更多
关键词 煤矿智能掘进 掘进就是掘模型 智能掘进机器人 智能导航 智能支护 多任务协同控制
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基于机器学习的油藏动态分析研究
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作者 王小燕 谢文昊 +1 位作者 李娟妮 王亦鑫 《现代电子技术》 北大核心 2025年第14期117-122,共6页
针对油藏开发过程中,传统储量预测方法精度低、复杂度高,以及人工分析信息滞后导致不能及时发现潜力井等问题,提出一种智能化油藏动态分析方法,实现油藏开发问题的实时精确处理。在油田生产过程采集的20个参数中,利用皮尔逊相关系数最... 针对油藏开发过程中,传统储量预测方法精度低、复杂度高,以及人工分析信息滞后导致不能及时发现潜力井等问题,提出一种智能化油藏动态分析方法,实现油藏开发问题的实时精确处理。在油田生产过程采集的20个参数中,利用皮尔逊相关系数最终选用当前年产油量、含水、体积液量、累产油量、排量、冲次和泵效共7个参数表征油田生产能力。然后基于回归的支持向量机模型,利用不同核函数下的SVR模型对油田月产油量进行预测,最终选定超参数d=2、C=54的二阶多项式核函数下的SVR模型作为最优的油田月产量预测模型,该模型预测结果的平均绝对误差为-0.0061,均方误差为-0.1028。实验结果表明,智能化油藏动态分析方法在勘探数据分析的基础上,能够准确地动态预测油藏,优化勘探规划结构并提高油藏发现效率。 展开更多
关键词 智能油田 油藏动态分析 油田产量预测 支持向量机模型 核函数 皮尔逊相关系数
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