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Optimization model of unascertained measurement for underground mining method selection and its application 被引量:6
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作者 刘爱华 董蕾 董陇军 《Journal of Central South University》 SCIE EI CAS 2010年第4期744-749,共6页
An optimization model of underground mining method selection was established on the basis of the unascertained measurement theory.Considering the geologic conditions,technology,economy and safety production,ten main f... An optimization model of underground mining method selection was established on the basis of the unascertained measurement theory.Considering the geologic conditions,technology,economy and safety production,ten main factors influencing the selection of mining method were taken into account,and the comprehensive evaluation index system of mining method selection was constructed.The unascertained evaluation indices corresponding to the selected factors for the actual situation were solved both qualitatively and quantitatively.New measurement standards were constructed.Then,the unascertained measurement function of each evaluation index was established.The index weights of the factors were calculated by entropy theory,and credible degree recognition criteria were established according to the unascertained measurement theory.The results of mining method evaluation were obtained using the credible degree criteria,thus the best underground mining method was determined.Furthermore,this model was employed for the comprehensive evaluation and selection of the chosen standard mining methods in Xinli Gold Mine in Sanshandao of China.The results show that the relative superiority degrees of mining methods can be calculated using the unascertained measurement optimization model,so the optimal method can be easily determined.Meanwhile,the proposed method can take into account large amount of uncertain information in mining method selection,which can provide an effective way for selecting the optimal underground mining method. 展开更多
关键词 mining engineering underground mining method optimization model unascertained measurement theory information entropy
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Soft measurement model of ring's dimensions for vertical hot ring rolling process using neural networks optimized by genetic algorithm 被引量:2
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作者 汪小凯 华林 +3 位作者 汪晓旋 梅雪松 朱乾浩 戴玉同 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期17-29,共13页
Vertical hot ring rolling(VHRR) process has the characteristics of nonlinearity,time-variation and being susceptible to disturbance.Furthermore,the ring's growth is quite fast within a short time,and the rolled ri... Vertical hot ring rolling(VHRR) process has the characteristics of nonlinearity,time-variation and being susceptible to disturbance.Furthermore,the ring's growth is quite fast within a short time,and the rolled ring's position is asymmetrical.All of these cause that the ring's dimensions cannot be measured directly.Through analyzing the relationships among the dimensions of ring blanks,the positions of rolls and the ring's inner and outer diameter,the soft measurement model of ring's dimensions is established based on the radial basis function neural network(RBFNN).A mass of data samples are obtained from VHRR finite element(FE) simulations to train and test the soft measurement NN model,and the model's structure parameters are deduced and optimized by genetic algorithm(GA).Finally,the soft measurement system of ring's dimensions is established and validated by the VHRR experiments.The ring's dimensions were measured artificially and calculated by the soft measurement NN model.The results show that the calculation values of GA-RBFNN model are close to the artificial measurement data.In addition,the calculation accuracy of GA-RBFNN model is higher than that of RBFNN model.The research results suggest that the soft measurement NN model has high precision and flexibility.The research can provide practical methods and theoretical guidance for the accurate measurement of VHRR process. 展开更多
关键词 vertical hot ring rolling dimension precision soft measurement model artificial neural network genetic algorithm
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Orbcomm机会信号观测噪声评估与差分定位分析
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作者 谢阳 李广云 +1 位作者 陈明剑 周玟龙 《导航定位学报》 北大核心 2025年第5期49-58,共10页
为了进一步提高全球卫星导航系统(GNSS)的定位精度,分析低地球轨道(LEO)卫星机会信号的观测噪声水平及其对定位性能的影响:基于轨道通信卫星(Orbcomm)平方信号设计码跟踪环路,优化信号跟踪环路效率;然后提出伪距速率和载波相位的单站观... 为了进一步提高全球卫星导航系统(GNSS)的定位精度,分析低地球轨道(LEO)卫星机会信号的观测噪声水平及其对定位性能的影响:基于轨道通信卫星(Orbcomm)平方信号设计码跟踪环路,优化信号跟踪环路效率;然后提出伪距速率和载波相位的单站观测噪声提取方法,建立载噪比相关的随机模型,并推导线性锁相环相位噪声表达式。实验结果表明:载噪比相关的随机模型能够有效反映观测噪声的分布特性;当信号载噪比大于45 dB.Hz时,伪距速率和载波相位的观测噪声分别优于0.2 m/s和1.4 cm;短基线差分定位结果表明,伪距速率定位受残留系统误差的影响较小,所提出的随机模型能够有效提高其定位性能,且在相同信号来源和采样率的条件下,载波相位的定位均方根误差(RMSE)可达到米级,优于伪距速率定位性能。 展开更多
关键词 低地球轨道(LEO) 轨道通信卫星(Orbcomm) 伪距速率 载波相位 观测噪声 随机模型
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Position Adaptive Measurement Model for Double-four Quadrant Photoelectric Detector
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作者 党丽萍 刘君华 +1 位作者 唐树刚 刘洪飞 《Defence Technology(防务技术)》 SCIE EI CAS 2006年第2期106-111,共6页
A modeling method of the support vector machine combined with matrix optics is considered; a complete new measurement model for double-four quadrant photoelectric detector is built. According to the analysis of the re... A modeling method of the support vector machine combined with matrix optics is considered; a complete new measurement model for double-four quadrant photoelectric detector is built. According to the analysis of the received light spot size and its motion with the changes of the defocusing amount of detector photosensitive surface and the detector position attitude in the optical path, a mathematic expression of photoelectrical conversion is given, which can be applicable to random setting position of the detector at any time. Based on least square support vector machine (LS SVM), the mapping relationship among the output signal linear characteristic parameters (zero neighborhood gradient and intercept), the defocusing amount of the detector and the installation position attitude angle is established. Thus, the multiple dimensional high accuracy measuring and adjusting control system can be left out, and adaptive measurement of the detector parameters can be realized. Compared with existed measurement model and method, the presented model has the advantages of more clear physical meaning, closer to work mechanism of detector, acquiring more complete sample data and wiping out the dead spots or bad spots in measurement. And the accuracy of displacement measurement is increased to 3?μm. At the same time, this measurement mode provides a technical shortcut for three-dimensional small angle measurement. 展开更多
关键词 光电探测器 位置适应管理 管理模型 无线电导引 线性参数
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Dynamic grey model of verification cycle and lifecycle of measuring instrument and its application 被引量:4
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作者 苏海涛 杨世元 +1 位作者 董华 沈毛虎 《Journal of Central South University》 SCIE EI CAS 2005年第S2期86-89,共4页
Two dynamic grey models DGM (1, 1) for the verification cycle and the lifecycle of measuring instrument based on time sequence and frequency sequence were set up, according to the statistical feature of examination da... Two dynamic grey models DGM (1, 1) for the verification cycle and the lifecycle of measuring instrument based on time sequence and frequency sequence were set up, according to the statistical feature of examination data and weighting method. By a specific case, i.e. vernier caliper, it is proved that the fit precision and forecast precision of the models are much higher, the cycles are obviously different under different working conditions, and the forecast result of the frequency sequence model is better than that of the time sequence model. Combining dynamic grey model and auto-manufacturing case the controlling and information subsystems of verification cycle and the lifecycle based on information integration, multi-sensor controlling and management controlling were given. The models can be used in production process to help enterprise reduce error, cost and flaw. 展开更多
关键词 measuring equipment verification cycle LIFECYCLE dynamic grey model qualification rate information system
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Integrating unascertained measurement and information entropy theory to assess blastability of rock mass 被引量:15
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作者 周健 李夕兵 《Journal of Central South University》 SCIE EI CAS 2012年第7期1953-1960,共8页
Due to the complex features of rock mass blastability assessment systems, an evaluation model of rock mass blastability was established on the basis of the unascertained measurement (UM) theory and the actual charac... Due to the complex features of rock mass blastability assessment systems, an evaluation model of rock mass blastability was established on the basis of the unascertained measurement (UM) theory and the actual characteristics of the project. Considering a comprehensive range of intact rock properties and discontinuous structures of rock mass, twelve main factors influencing the evaluation blastability of rock mass were taken into account in the UM model, and the blastability evaluation index system of rock mass was constructed. The unascertained evaluation indices corresponding to the selected factors for the actual situation were solved both qualitatively and quantitatively. Then, the UM function of each evaluation index was obtained based on the initial data for the analysis of the blastability of six rock mass at a highway improvement cutting site in North Wales. The index weights of the factors were calculated by entropy theory, and credible degree identification (CDI) criteria were established according to the UM theory. The results of rock mass blastability evaluation were obtained by the CDI criteria. The results show that the UM model assessment results agree well with the actual records, and are consistent with those of the fuzzy sets evaluation method. Meanwhile, the unascertained superiority degree of rock mass blastability of samples S1-$6 which can be calculated by scoring criteria are 3.428 5, 3.453 3, 4.058 7, 3.675 9, 3.516 7 and 3.289 7, respectively. Furthermore, the proposed method can take into account large amount of uncertain information in blastability evaluation, which can provide an effective, credible and feasible way for estimating the blastability of rock mass. Engineering practices show that it can complete the blastability assessment systematically and scientifically without any assumption by the proposed model, which can be applied to practical engineering. 展开更多
关键词 rock mass BLASTABILITY unascertained measurement (UM) model information entropy PREDICTION
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t/k-fault diagnosis algorithm of n-dimensional hypercube network based on the MM*model 被引量:4
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作者 LIANG Jiarong ZHOU Ning YUN Long 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第1期216-222,共7页
Compared with accurate diagnosis, the system’s selfdiagnosing capability can be greatly increased through the t/kdiagnosis strategy at most k vertexes to be mistakenly identified as faulty under the comparison model,... Compared with accurate diagnosis, the system’s selfdiagnosing capability can be greatly increased through the t/kdiagnosis strategy at most k vertexes to be mistakenly identified as faulty under the comparison model, where k is typically a small number. Based on the Preparata, Metze, and Chien(PMC)model, the n-dimensional hypercube network is proved to be t/kdiagnosable. In this paper, based on the Maeng and Malek(MM)*model, a novel t/k-fault diagnosis(1≤k≤4) algorithm of ndimensional hypercube, called t/k-MM*-DIAG, is proposed to isolate all faulty processors within the set of nodes, among which the number of fault-free nodes identified wrongly as faulty is at most k. The time complexity in our algorithm is only O(2~n n~2). 展开更多
关键词 hypercube network t/k-diagnosis algorithm multiprocessor systems the Maeng and Malek(mm)* model Preparata Metze and Chien(PMC)
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Tracking a maneuvering target in clutter with out-of-sequence measurements for airborne radar 被引量:3
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作者 Weihua Wu Jing Jiang Yang Wan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第4期746-753,共8页
There are many proposed optimal or suboptimal al- gorithms to update out-of-sequence measurement(s) (OoSM(s)) for linear-Gaussian systems, but few algorithms are dedicated to track a maneuvering target in clutte... There are many proposed optimal or suboptimal al- gorithms to update out-of-sequence measurement(s) (OoSM(s)) for linear-Gaussian systems, but few algorithms are dedicated to track a maneuvering target in clutter by using OoSMs. In order to address the nonlinear OoSMs obtained by the airborne radar located on a moving platform from a maneuvering target in clut- ter, an interacting multiple model probabilistic data association (IMMPDA) algorithm with the OoSM is developed. To be practical, the algorithm is based on the Earth-centered Earth-fixed (ECEF) coordinate system where it considers the effect of the platform's attitude and the curvature of the Earth. The proposed method is validated through the Monte Carlo test compared with the perfor- mance of the standard IMMPDA algorithm ignoring the OoSM, and the conclusions show that using the OoSM can improve the track- ing performance, and the shorter the lag step is, the greater degree the performance is improved, but when the lag step is large, the performance is not improved any more by using the OoSM, which can provide some references for engineering application. 展开更多
关键词 out-of-sequence measurement(s) (OoSM(s)) Earth-centered Earth-fixed (ECEF) interacting multiple model (Imm) probabilistic data association (PDA) attitude.
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Micro-failure process and failure mechanism of brittle rock under uniaxial compression using continuous real-time wave velocity measurement 被引量:4
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作者 WU Zhi-jun WANG Zhi-yang +2 位作者 FAN Li-feng WENG Lei LIU Quan-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期556-571,共16页
In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indi... In this study,the micro-failure process and failure mechanism of a typical brittle rock under uniaxial compression are investigated via continuous real-time measurement of wave velocities.The experimental results indicate that the evolutions of wave velocities became progressively anisotropic under uniaxial loading due to the direction-dependent development of micro-damage.A wave velocity model considering the inner anisotropic crack evolution is proposed to accurately describe the variations of wave velocities during uniaxial compression testing.Based on which,the effective elastic parameters are inferred by a transverse isotropic constitutive model,and the evolutions of the crack density are inversed using a self-consistent damage model.It is found that the propagation of axial cracks dominates the failure process of brittle rock under uniaxial loading and oblique shear cracks develop with the appearance of macrocrack. 展开更多
关键词 elastic wave velocity brittle rock failure uniaxial compression test continuous real-time measurement anisotropic damage evolution theory and modelling
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A novel launch dynamics measurement system for multiple launch rocket system and comparative analysis with numerical simulations 被引量:3
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作者 Li-lin Gu Xiao-ting Rui +3 位作者 Guo-ping Wang Yi An Fu-feng Yang Min Wei 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第2期671-681,共11页
In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure ... In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS. 展开更多
关键词 Multiple launch rocket system Photoelectric sensor Launch dynamics measurement system model verification Transfer matrix method for multibody SYSTEMS
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Lifetime prediction for tantalum capacitors with multiple degradation measures and particle swarm optimization based grey model 被引量:2
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作者 黄姣英 高成 +1 位作者 崔嵬 梅亮 《Journal of Central South University》 SCIE EI CAS 2012年第5期1302-1310,共9页
A lifetime prediction method for high-reliability tantalum (Ta) capacitors was proposed, based on multiple degradation measures and grey model (GM). For analyzing performance degradation data, a two-parameter mode... A lifetime prediction method for high-reliability tantalum (Ta) capacitors was proposed, based on multiple degradation measures and grey model (GM). For analyzing performance degradation data, a two-parameter model based on GM was developed. In order to improve the prediction accuracy of the two-parameter model, parameter selection based on particle swarm optimization (PSO) was used. Then, the new PSO-GM(1, 2, co) optimization model was constructed, which was validated experimentally by conducting an accelerated testing on the Ta capacitors. The experiments were conducted at three different stress levels of 85, 120, and 145℃. The results of two experiments were used in estimating the parameters. And the reliability of the Ta capacitors was estimated at the same stress conditions of the third experiment. The results indicate that the proposed method is valid and accurate. 展开更多
关键词 accelerated degradation test CAPACITOR multiple degradation measure particle swarm optimization grey model
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Emotional inference by means of Choquet integral and λ-fuzzy measurement in consideration of ambiguity of human mentality 被引量:1
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作者 KWON Il-kyoung LEE Sang-yong 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第1期160-168,共9页
Research on human emotions has started to address psychological aspects of human nature and has advanced to the point of designing various models that represent them quantitatively and systematically. Based on the fin... Research on human emotions has started to address psychological aspects of human nature and has advanced to the point of designing various models that represent them quantitatively and systematically. Based on the findings, a method is suggested for emotional space formation and emotional inference that enhance the quality and maximize the reality of emotion-based personalized services. In consideration of the subjective tendencies of individuals, AHP was adopted for the quantitative evaluation of human emotions, based on which an emotional space remodeling method is suggested in reference to the emotional model of Thayer and Plutchik, which takes into account personal emotions. In addition, Sugeno fuzzy inference, fuzzy measures, and Choquet integral were adopted for emotional inference in the remodeled personalized emotional space model. Its performance was evaluated through an experiment. Fourteen cases were analyzed with 4.0 and higher evaluation value of emotions inferred, for the evaluation of emotional similarity, through the case studies of 17 kinds of emotional inference methods. Matching results per inference method in ten cases accounting for 71% are confirmed. It is also found that the remaining two cases are inferred as adjoining emotion in the same section. In this manner, the similarity of inference results is verified. 展开更多
关键词 fuzzy measure fuzzy integral emotional model emotion space AHP fuzzy inference system Choquet integral
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Design and dynamic analysis of single-axis integrated inertia measurement device 被引量:2
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作者 Ma Zongmin Shi Yunbo +1 位作者 Meng Meiyu Liu Jun 《仪器仪表学报》 EI CAS CSCD 北大核心 2007年第9期1558-1563,共6页
The structure and measurement theory of a single-axis integrated inertia measurement device are discussed in this paper.The acceleration and angle velocity can be detected by the proposed sensor at the same time.The k... The structure and measurement theory of a single-axis integrated inertia measurement device are discussed in this paper.The acceleration and angle velocity can be detected by the proposed sensor at the same time.The ki- netic model of the device is also established.In addition,the signal generation of the single-axis integrated inertia measurement device is analyzed and simulated.The results of the model are consistent with simulation result. 展开更多
关键词 设计 动力学模型 单轴整合 惯性测量仪器 仿真分析
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A FGR Software Model for Measuring the Effect of Technological Progress
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作者 He Zhongxiong and John Wei(Northern Jiaotong University, Beijing, China) 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1990年第1期84-85,共2页
The work of quantitative studying the effect of technological progress on economic growth, being of great complexity and far-reaching significance, has become a quite popular research topic in the world. In recent yea... The work of quantitative studying the effect of technological progress on economic growth, being of great complexity and far-reaching significance, has become a quite popular research topic in the world. In recent years there are a large number of scientists who are engaged in this research both at home and abroad. 展开更多
关键词 FGR A FGR Software model for measuring the Effect of Technological Progress
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面向任务的CMM圆度测量不确定度建模与优化 被引量:1
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作者 程杰 沙跃兵 +1 位作者 周易明 程银宝 《电子测量技术》 北大核心 2024年第10期108-114,共7页
精密仪器正趋向于智能化以及功能多样化发展,评估精密仪器的测量不确定度因此也变得更加复杂。以CMM中的圆度测量为例,以面向任务的不确定度评定方法,实现快速、可靠地评估出CMM测量任务的不确定度。根据误差传播的实际情况,结合计算机... 精密仪器正趋向于智能化以及功能多样化发展,评估精密仪器的测量不确定度因此也变得更加复杂。以CMM中的圆度测量为例,以面向任务的不确定度评定方法,实现快速、可靠地评估出CMM测量任务的不确定度。根据误差传播的实际情况,结合计算机模拟的蒙特卡洛方法,提出了一种误差分布多状态下的不确定度代数和合成方法。针对测量不确定度初次评定存在过量估计的问题,提出了优化评估方案。给出圆度测量任务的不确定度评定与优化实例,验证评定模型和优化方法的可行性与有效性。系统性解决CMM面向任务的不确定度评定难题,对于解决其他高精度仪器测量结果的不确定度评估、提高仪器的实际使用价值,均具有重要参考意义。 展开更多
关键词 坐标测量机 精度 测量不确定度 数学模型 优化估计
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煤系氦气扩散机制及其对氦气富集的启示——以沁水盆地北部太原组为例 被引量:1
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作者 马勇 辛志源 +4 位作者 陈践发 李玉宏 张修涛 蒋浩杰 陈泽亚 《煤田地质与勘探》 北大核心 2025年第6期58-69,共12页
【目的】全球富氦气藏以常规天然气为主,近年来在我国鄂尔多斯盆地及周缘石炭−二叠系煤系中发现含氦天然气,揭示煤系氦气具有一定的资源潜力。但目前针对煤系氦气扩散运移机制的研究几乎处于空白,严重制约煤系氦气富集规律的进一步研究... 【目的】全球富氦气藏以常规天然气为主,近年来在我国鄂尔多斯盆地及周缘石炭−二叠系煤系中发现含氦天然气,揭示煤系氦气具有一定的资源潜力。但目前针对煤系氦气扩散运移机制的研究几乎处于空白,严重制约煤系氦气富集规律的进一步研究。【方法】以沁水盆地北部太原组煤及其顶板泥岩为研究对象,开展不同含水饱和度及气体含量(体积分数)煤系氦气物理扩散实验,并结合区域沉积埋藏史及生烃演化史模拟计算煤与泥岩中氦气扩散通量,揭示煤系氦气富集机制。【结果和结论】(1)实验温压条件下(20℃,气体压力为1 MPa),在≤13.5 nm孔隙中氦气以Knudsen扩散为主,煤与泥岩中氦气的扩散速率相近;在>13.5 nm孔隙中氦气转为Fick扩散。煤系氦气扩散主要受孔隙结构、含水性和气体含量影响,孔隙连通性越差、含水饱和度越高、氦气含量越低,氦气扩散越慢,封闭能力越强。(2)煤中割理−裂缝系统发育,连通性较好,导致煤中氦气扩散系数(1.1×10^(−8)m^(2)/s)高于泥岩(5.8×10^(−9)m^(2)/s)。高含水性通过阻塞孔隙通道和改变气−液界面行为降低氦气扩散速率,而气体含量对扩散速率的影响主要与气体分压和氦气与甲烷物理性质差异有关。(3)结合物理模拟和数值模拟结果,建立了地质历史时期氦气扩散通量预测模型,标准状态下煤和泥岩中的氦气扩散通量分别为13.24、5.05 cm^(3)/m^(2),氦气扩散主要发生在含量较高的烃类生成初期,后期逸散量可忽略不计。(4)煤系生氦能力较弱,煤系氦气的富集成藏是外源补给与保存动态平衡的结果,深部断裂促进深部氦气向上运移,而低含量梯度、高含水饱和度及低连通性通过抑制扩散速率而增强氦气的封存能力。煤系氦气勘探需重点关注深部断裂系统沟通能力及盖层封存有效性。 展开更多
关键词 煤系氦气 扩散机制 扩散通量 预测模型 富集机理
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大语言模型安全性:分类、评估、归因、缓解、展望 被引量:7
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作者 黄河燕 李思霖 +7 位作者 兰天伟 邱昱力 柳泽明 姚嘉树 曾理 单赢宇 施晓明 郭宇航 《智能系统学报》 北大核心 2025年第1期2-32,共31页
大语言模型能够在多个领域及任务上给出与人类水平相当的解答,并且在未经训练的领域和任务上展现了丰富的涌现能力。然而,目前基于大语言模型的人工智能系统存在许多安全性隐患,例如大语言模型系统容易受到难以被察觉的攻击,模型生成的... 大语言模型能够在多个领域及任务上给出与人类水平相当的解答,并且在未经训练的领域和任务上展现了丰富的涌现能力。然而,目前基于大语言模型的人工智能系统存在许多安全性隐患,例如大语言模型系统容易受到难以被察觉的攻击,模型生成的内容存在违法、泄密、仇恨、偏见、错误等问题。并且在实际应用中,大语言模型可能被滥用,生成的内容可能引起国家、人群和领域等多个层面的困扰。本文旨在深入探讨大语言模型面临的安全性风险并进行分类,回顾现有的评估方法,研究安全性风险背后的因果机制,并总结现有的解决措施。具体而言,本文明确了大语言模型面临的10种安全性风险,并将其归类为模型自身安全性风险与生成内容的安全性风险两个方面,并对每种风险进行了详细的分析和讲解。此外,本文还从生命周期和危害程度两个角度对大语言模型的安全风险进行了系统化的分析,并介绍了现有的大语言模型安全风险评估方法、大语言模型安全风险的出现原因以及相应的缓解措施。大语言模型的安全风险是亟待解决的重要问题。 展开更多
关键词 大语言模型 模型自身安全性 生成内容安全性 安全性分类 安全性风险评估 安全性风险归因 安全性风险缓解措施 安全性研究展望
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基于大直径钻孔钻进多参量的煤体应力钻测方法 被引量:1
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作者 赵同彬 赵志刚 +3 位作者 齐炎山 尹延春 牛旭 李淇凡 《煤炭科学技术》 北大核心 2025年第1期122-132,共11页
煤体高应力是冲击地压发生的必要条件,及时准确测量评估煤体应力是冲击地压预警工作的关键环节。大直径钻孔是煤矿冲击地压防治最常用的预卸压、卸压解危和应力调控方法,研发和应用基于大直径卸压钻孔的煤体应力随钻测量技术方法,可以... 煤体高应力是冲击地压发生的必要条件,及时准确测量评估煤体应力是冲击地压预警工作的关键环节。大直径钻孔是煤矿冲击地压防治最常用的预卸压、卸压解危和应力调控方法,研发和应用基于大直径卸压钻孔的煤体应力随钻测量技术方法,可以得到煤矿井下大量煤体应力数据。本文根据煤体钻削破坏特征,对钻头破煤进行了力学分析,以钻头钻削力为纽带,研究了钻头受力与煤体应力关系,建立了煤体钻削力学模型,给出了包含钻进多参量的煤体应力反演方程;开展不同强度和煤体应力的原煤室内钻进实验,验证了力学模型的准确性和适用性,自主研制了大直径卸压钻机配套的随钻测量装置,开展煤矿井下实测实验,获取钻头位移、转速、转矩随时间变化数据,计算得到不同钻孔深度的煤体应力,给出了卸压孔区应力场分布形态,并与钻进能量和钻进时间进行了比较分析。结果表明,室内钻进实验加载应力与钻削力学模型计算应力平均误差为4.9%、最大误差为15.7%;现场实测煤体应力随孔深呈现先上升后下降的趋势,与煤壁支承压力分布规律一致,同一钻孔的煤体应力、钻进时间和钻进能量随孔深变化曲线基本一致,表明高应力区钻孔消耗能量较多,所需钻进时间也较长;对比相邻钻孔应力发现,先施工钻孔的应力峰值较高,后施工钻孔应力峰值较低,且峰值位置向深部转移,表明先施工钻孔起到明显的卸压作用。通过建立钻进多参量和煤体应力的定量关系,进行基于大直径卸压钻孔钻进多参量的煤体应力原位测量,将大直径卸压钻孔从卸压工程孔拓展为应力测量孔,实现钻孔卸压与应力测量评估一体化。 展开更多
关键词 大直径卸压钻孔 钻削力学模型 煤体应力 钻进多参量 钻测方法
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中国综合交通清洁低碳发展对策及减排效果评估与展望 被引量:1
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作者 乔冰 林晶晶 《中国航海》 北大核心 2025年第2期151-158,共8页
综合交通清洁低碳发展对于防控与缓解危害人类可持续健康发展的大气环境问题具有重大意义,为此依据主管部门公开的铁路、公路、水路、民航、城市等5种运输方式的统计数据、可持续发展报告、污染防治规划,分别设定了铁水联运、中欧班列... 综合交通清洁低碳发展对于防控与缓解危害人类可持续健康发展的大气环境问题具有重大意义,为此依据主管部门公开的铁路、公路、水路、民航、城市等5种运输方式的统计数据、可持续发展报告、污染防治规划,分别设定了铁水联运、中欧班列、高铁客运、电子不停车收费(ETC)、车用燃料质量提升、港口效率提升、海运能效提升、船舶燃油质量提升、固液散货码头污染治理减排、民航节能减排能力提升、电动公交、轨道交通等12种关于清洁低碳发展的对策情景,提出了基于燃料法-运输能耗-排放因子-替代运输量的空气污染物及温室气体减排量计算模式和基于类比及统计分析等方法的12种对策情景减排量估算方法,根据估算的2013年以来的燃油及空气污染物和CO_(2)的减排量,对综合交通清洁低碳发展的成效进行了回顾,针对面临的问题与挑战对综合交通清洁低碳的发展做出了展望。 展开更多
关键词 交通清洁低碳发展 减排量 空气污染物 温室气体 减排对策 计算模型
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基于改进Crossformer伪量测构建的主动配电网预测辅助状态估计方法 被引量:1
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作者 王玥 于越 +1 位作者 郭嘉辉 金朝阳 《高电压技术》 北大核心 2025年第6期2999-3009,I0031-I0033,共14页
为了解决高比例分布式电源(distributed generation,DG)大规模并网后实时量测数目缺失、传统预测辅助状态估计方法(forecasting-aided state estimation,FASE)估计精度有限等问题,提出了基于改进Crossformer伪量测构建的主动配电网FASE... 为了解决高比例分布式电源(distributed generation,DG)大规模并网后实时量测数目缺失、传统预测辅助状态估计方法(forecasting-aided state estimation,FASE)估计精度有限等问题,提出了基于改进Crossformer伪量测构建的主动配电网FASE方法。首先,基于最大信息系数法(maximal information coefficient,MIC)筛选出高相关性的输入特征,提高预测模型的精度;然后,通过全变差正则化技术(total variation regularized,TV)优化鲁棒主成分分析法(robust principal component analysis,RPCA),构建TRPCA层,并将其嵌入到Crossformer中,以填补Crossformer无法有效处理非高斯噪声的空白;最后,利用改进的预测模型进行超短期负荷预测,经潮流计算得到节点伪量测,在量测不足情况下补全缺失数据,并结合扩展卡尔曼滤波器(extended Kalman filter,EKF)进行状态估计。在IEEE 33节点和IEEE 118节点标准配电网上进行仿真测试,结果表明所提方法在估计精度和鲁棒性等方面具有一定优势,可为主动配电网FASE提供参考。 展开更多
关键词 主动配电网 预测辅助状态估计 伪量测构建 Crossformer 鲁棒主成分分析 扩展卡尔曼滤波器
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