A method for predicting the water-flowing fractured zone height based on an improved key stratum theory

In the process of using the original key stratum theory to predict the height of a water-flowing fractured zone(WFZ),the influence of rock strata outside the calculation range on the rock strata within the calculation range as well as the fact that the shape of the overburden deformation area will change with the excavation length are ignored.In this paper,an improved key stratum theory(IKS theory)was proposed by fixing these two shortcomings.Then,a WFZ height prediction method based on IKS theory was established and applied.First,the range of overburden involved in the analysis was determined according to the tensile stress distribution range above the goaf.Second,the key stratum in the overburden involved in the analysis was identified through IKS theory.Finally,the tendency of the WFZ to develop upward was determined by judging whether or not the identified key stratum will break.The proposed method was applied and verified in a mining case study,and the reasons for the differences in the development patterns between the WFZs in coalfields in Northwest and East China were also fully explained by this method.

A Heterogeneous Information Fusion Method for Maritime Radar and AIS Based on D-S Evidence Theory

Maritime radar and automatic identification systems (AIS), which are essential auxiliary equipment for navigation safety in the shipping industry, have played significant roles in maritime safety supervision. However, in practical applications, the information obtained by a single device is limited, and it is necessary to integrate the information of maritime radar and AIS messages to achieve better recognition effects. In this study, the D-S evidence theory is used to fusion the two kinds of heterogeneous information: maritime radar images and AIS messages. Firstly, the radar image and AIS message are processed to get the targets of interest in the same coordinate system. Then, the coordinate position and heading of targets are chosen as the indicators for judging target similarity. Finally, a piece of D-S evidence theory based on the information fusion method is proposed to match the radar target and the AIS target of the same ship. Particularly, the effectiveness of the proposed method has been validated and evaluated through several experiments, which proves that such a method is practical in maritime safety supervision.

基于层次分析法与改进D-S理论的阀水冷系统状态评估

为了及时评估保障换流阀可靠运行的阀水冷系统运行状态,首先,分析了换流站阀水冷系统整体构成,选取主要历史数据和实时数据构建了评估指标体系,通过三角形函数和半梯形函数以及专家调查法确定各个指标的隶属度;其次,基于层次分析法确定各个评估指标权重,改进D-S理论建立阀水冷系统运行状态评估模型;最后,通过采集实际工程阀水冷系统主要指标数据对模型进行了验证,并以阀水冷系统滤芯清洗前后数据为例对评估结果进行了对比。结果表明,所建模型能够对阀水冷系统运行状态做出准确识别和评估,有利于运维人员及时掌控阀水冷系统运行状态,保障其可靠运行。

Fault Isolation of Light Rail Vehicle Suspension System Based on D-S Evidence Theory and Improvement Application Case

This paper presents an innovative approach for the fault isolation of Light Rail Vehicle (LRV) suspension system based on the Dempster-Shafer (D-S) evidence theory and its improvement application case. The considered LRV has three rolling stocks and each one equips three sensors for monitoring the suspension system. A Kalman filter is applied to generate the residuals for fault diagnosis. For the purpose of fault isolation, a fault feature database is built in advance. The Eros and the norm distance between the fault feature of the new occurred fault and the one in the feature database are applied to measure the similarity of the feature which is the basis for the basic belief assignment to the fault, respectively. After the basic belief assignments are obtained, they are fused by using the D-S evidence theory. The fusion of the basic belief assignments increases the isolation accuracy significantly. The efficiency of the proposed method is demonstrated by two case studies.

Improved Ligand-Field Theory with Effect of Electron-Phonon Interaction

Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.

基于PSO-GRNN和D-S证据理论的电网分区故障诊断

针对大电网中保护和断路器误动、拒动、信息丢失等不确定的电网故障信息以及现有电网分区方法的不足,提出了基于粒子群优化广义回归神经网络(PSO-GRNN)和D-S证据理论的电网分区故障诊断方法。首先,通过改进图形分割法将大电网划分为相互重叠的不同区域,降低故障诊断难度。然后在各个区域建立PSOGRNN诊断模块,根据故障警报信息,并行完成各自的故障诊断任务。最后,采用D-S证据理论对相邻区域的重叠区域进行分析,以实现对重叠区域的综合故障诊断。仿真结果表明,该方法能有效识别非重叠区域和重叠区域的故障,容错能力强,诊断准确率高。

Unified Water Gravity Wave Theory and Improved Linear Wave

Based on Least Square Method, this paper presents variational principle for handling various water gravity wave theories and the unified water gravity wave theory was given. By using this variational principle of unified water wave theory, two kinds of improved linear waves were derived. The first one uses the same boundary conditions which were applied to derive 5-order Stokes wave. The second one uses the accurate boundary conditions (Eqs. 11 and 12). The two improved linear waves were compared with the existing linear wave.

Risk Assessment of Agricultural Products Supply-Chain Finance Based on D-S Theory

Agricultural products supply-chain finance, as one of the solutions to the issue of “capital problems” of agriculture, countryside and farmers, has proposed a kind of characteristics model to assess the risk of agricultural production, processing and marketing, which can improve the issue of farmers and enterprises lacking of funds. This model is proposed on the basis of uncertain information processing method of D-S theory and its data combination rules, combined with the “discount rate” correction model, and it includes a risk assessment index system of agricultural products supply-chain finance, fully considering the five aspects of production, processing, marketing, cooperation of supply chain and collateral. At last, a taro supply chain is taken for example. And the risk assessment of its supply-chain finance based on this model has been discussed in detail. And the result has proved that the model and its algorithm are practical and feasible.

Large Power Transformer Fault Diagnosis and Prognostic Based on DBNC and D-S Evidence Theory

Power transformer is a core equipment of power system, which undertakes the important functions of power transmission and transformation, and its safe and stable operation has great significance to the normal operation of the whole power system. Due to the complex structure of the transformer, the use of single information for condition-based maintenance (CBM) has certain limitations, with the help of advanced sensor monitoring and information fusion technology, multi-source information is applied to the prognostic and health management (PHM) of power transformer, which is an important way to realize the CBM of power transformer. This paper presents a method which combine deep belief network classifier (DBNC) and D-S evidence theory, and it is applied to the PHM of the large power transformer. The experimental results show that the proposed method has a high correct rate of fault diagnosis for the power transformer with a large number of multi-source data.

Risk assessment of water security in Haihe River Basin during drought periods based on D-S evidence theory

The weights of the drought risk index （DRI）, which linearly combines the reliability, resiliency, and vulnerability, are difficult to obtain due to complexities in water security during drought periods. Therefore, drought entropy was used to determine the weights of the three critical indices. Conventional simulation results regarding the risk load of water security during drought periods were often regarded as precise. However, neither the simulation process nor the DRI gives any consideration to uncertainties in drought events. Therefore, the Dempster-Shafer （D-S） evidence theory and the evidential reasoning algorithm were introduced, and the DRI values were calculated with consideration of uncertainties of the three indices. The drought entropy and evidential reasoning algorithm were used in a case study of the Haihe River Basin to assess water security risks during drought periods. The results of the new DRI values in two scenarios were compared and analyzed. It is shown that the values of the DRI in the D-S evidence algorithm increase slightly from the original results of Zhang et al. （2005）, and the results of risk assessment of water security during drought periods are reasonable according to the situation in the study area. This study can serve as a reference for further practical application and planning in the Haihe River Basin, and other relevant or similar studies.

基于改进D-S证据理论的变电站继电保护二次回路故障诊断方法研究

改进D-S证据理论基础上的智能变电站继电保护二次回路故障诊断方法,对故障元件集合中的各元件故障引发概率进行判断,从而进一步完成二次回路整体的故障判断。同时,基于D-S证据理论,能够有效解决证据冲突问题,保证计算结果符合逻辑。具体来说,基于D-S理论开展继电保护二次回路故障诊断工作时,需完成SCD文件的初始化解析,有效检测继电保护故障,应用虚回路通信状态和举证表获得故障元件集合信息,进一步判定可疑故障元件集合中的故障可信度,完成整个故障诊断过程。基于此,分析改进D-S证据理论应用的各项优势,进一步研究改进D-S的证据理论变电站继电保护二次回路故障诊断步骤。

Study on Evaluation Method of Teaching Quality Based on Cloud Model and D-S Theory

The Evaluation of teaching quality is a complicated project. It’s a typical problem of uncertainty. A design scheme of teaching quality evaluation method based on cloud model and D-S theory is proposed with the school teaching evaluation index. With the experiences and knowledge of experts, evaluation index was described by cloud model and judgment matrix of AHP was revised by D-S theory. The weight of evaluation indexes was determined reasonably and objectively. Applied in the actual environment, the method can make an accurate and efficient evaluation with a certain practical value.

Improved Ligand-Field Theoretical Calculations of R-Line Thermal Broadenings of MgO:Cr^(3+) and MgO:V^(2+)

With the values of parameters obtained from improved ligand-field theory,by taking into account all theirreducible representations and their components in EPI as well as all the levels and the admixtures of basic wavefunc-tions within d^3 electronic configuration,the R-line thermal broadenings(TB)of both MgO:Cr^(3+)and MgO:V^(2+)havemicroscopic-theoretically been calculated.The results are in very good agreement with the experimental data.It is foundthat the R-line TB of MgO:Cr^(3+)or MgO:V^(2+)comes from the first-order term of EPI.The elastic Raman scattering ofacoustic phonons plays a dominant role in R-line TB of MgO:Cr^(3+)or MgO:V^(2+).

Improved Ligand-Field Calculation of Energy Spectrum and R-Line Thermal Shift of MgO：Cr^3＋

传统的 ligand 地理论不得不被考虑纯电子贡献和电子声子相互作用一改善(包括的 lattice-vibrationalrelaxation 精力) 。借助于改进 ligand 地理论， R 线， t_2~3 ~ 2T_1 线， t_2~2 (~ 3T_1 ) e~4T_2，和 t_2~2 (~ 3T_1 ) e~4T_1 乐队，地面状态 g 因素，四 strain-inducedlevel-splittings，和 MgO 的 R 线热移动:Cr~(3+) 被计算了。结果在对试验性的数据的很好的同意。它为 MgO 被发现那:Cr~(3+) ，贡献由于电子声子相互作用(EPI ) 来自一阶的条款。在 R-lineof MgO 的热移动:Cr~(3+) ，温度依赖者贡献由于 EPI 是主导的。

Improved Ligand-Field Theoretical Calculation of R-Line Pressure-Induced Shift of MgO:V^(2+)

By means of an improved ligand-field theory,the'pure electronic' PS and the PS due to EPI of R line ofMgO:V^(2+) have been calculated,respectively.The calculated results are in very good agreement with the experimentaldata.The behaviors of the pure electronic PS of R line of MgO:V^(2+) and the PS of its R line due to EPI are different.Itis the combined effect of them that gives rise to the total PS of R line,which has satisfactorily explained the experimentalresults.The mixing-degree of [t_2~2(~3T_1)e ~4T_2〉and [t_3~2 ~2E〉 in the wavefunction of R level and its variation with pressurehave been calculated and analyzed.The comparison between the feature of R-line PS of MgO:V^(2+) and that of MgO:Cr^(3+)has been made.

基于改进D-S证据理论的煤矿通风机故障诊断

为了提高煤矿通风机故障诊断的准确性,提出了一种基于改进证据理论信息融合的故障诊断方法。针对强冲突证据之间的合成问题,通过引入相容系数的概念,充分考虑证据间的相容性和冲突性,建立了一种新的证据权重的确定方法。在对原始证据进行修正后,由D-S证据理论合成规则进行融合决策。仿真结果表明,该方法可以有效识别出煤矿通风机的故障类型,且能避免误诊现象。

基于改进D-S证据理论的TOPSIS模型在科技奖励评价中的应用

针对科技奖励评价的特点,根据改进D-S证据合成规则,将专家的评价指标值转化为指标的综合得分并形成决策矩阵;结合TOPSIS模型求解理想解和负理想解,计算距离和贴近度,对各评价项目进行综合排名。实证结果表明:该模型能够很好地解决科技奖励评价过程中的不确定性问题,为科技奖励综合评价提供了一种新的思路。

D-S证据理论的改进算法在时-空信息融合中的应用

研究基于D-S证据理论的时-空信息融合,即多传感器多测量周期的信息融合,给出了三种时-空信息融合的方法:集中式、分布式无反馈和有反馈的融合算法。采用这些传统的时-空信息融合方法时,最终的融合结果会产生概率分配过分集中的现象,而且证据冲突时还会产生有悖常理的结果。本文在传统证据理论的合成公式的基础上给出了一个有效的合成规则,并由此提出了改进的融合方法。证据冲突的概率按照各个命题的平均支持程度加权进行分配,从而提高了融合结果的可靠性与合理性。

D-S证据理论融合改进BP网络的短期负荷预测研究

针对传统BP网络收敛速度较慢且实时性较差的缺点,在考虑了气候因素的情况下,分别用三种BP网络算法对某地区的负荷进行预测,通过对预测误差的分析,用证据理论的Dempster合成法则对算法进行融合,通过选取待预测日之前几天的数据作为融合样本,规定相应的基本信度函数,得到融合后的信度分配,从而决定相应时刻的预测模型,仿真结果表明,经过证据理论融合后选择的负荷预测算法具有更高的预测精度。

基于改进D-S证据理论的水下航行器声隐身性能评估

针对传统水下航行器声隐身性能评估方法计算时间长、实时性不强的缺点,将评估由数值计算问题变为基于多传感器信息融合的模式识别问题来解决。通过将改进D-S证据理论模型和图像欧氏距离模型相结合,提出了一种新的水下航行器声隐身性能快速评估方法。首先利用加速度传感器测得壳体表面振动信息,抽取分析频段内每个频带的功率作为特征向量,然后通过图像欧氏距离方法进行证据生成,最后用一种改进的D-S证据合成方法进行识别分类,快速评估出航行器当前的声隐身状态。并利用计算机仿真和水下振动实验相结合的方式,通过类柱体结构模拟航行器舱段,详细讨论了方法的先进性,并研究指出了需要改进的问题。探讨了一种水下航行器声隐身性能快速评估的实现方法。