Structural dynamic reliability evaluation under consideration of fuzzy strength and fuzzy stress

A new dynamic reliability analysis under repeated or multiple series fuzzy loads and fuzzy strength is proposed in this paper. The proposed prediction models of structural dynamic fuzzy reliability with and without strength degeneration are established by using fuzzy theory and stress-strength interference theory. The fuzzy reliability is converted to probability reliability. The results have shown that the proposed model is feasible and practicable

Multiplicity of positive solutions for quasilinear elliptic equations involving critical nonlinearity

AbstractWe are concerned with the following quasilinear elliptic equation$$\begin{array}{} \displaystyle -{\it\Delta} u-{\it\Delta}(u^{2})u=\mu |u|^{q-2}u+|u|^{2\cdot 2^*-2}u, u\in H_0^1({\it\Omega}), \end{array}$$(QSE)whereΩ⊂ ℝNis a bounded domain,N≥ 3,qN 0 such that (QSE) admits at least catΩ(Ω) positive solutions whenμ∈ (0,μ*)

On-line detection method for outliers of dynamic instability measurement data in geological exploration control process

Considering the characteristics of the vibration data detected by the unstable regulation process in the grinding and grading control system and the shortcomings of the traditional wavelet anomaly detection method, an online anomaly detection method combining autoregressive and wavelet analysis is proposed. By introducing the improved robust AR model, this method can overcome the problem that the time and frequency of traditional anomaly detection using wavelet analysis method cannot be well balanced and ensure the rationality of normal detection of process data. Considering the characteristics of parameter change and dynamic characteristics in the process of grinding and grading, the proposed method has the ability of on-line detection and parameter updating in real time, which ensures the control parameters of time-varying process control system. In order to avoid the problem that the traditional anomaly detection method needs to set the detection threshold, introduce the HMM to analyse the wavelet coefficients and update the HMM parameters online, which can ensure that the HMM can well reflect the distribution of the abnormal value of the process data. Through the experiment and application, it is proven that the anomaly data detection method proposed in this paper is more suitable for the detection data in the process of unstable regulation

Study on Influence of Residual Magnetite in Panzhihua Ilmenite Flotation

AbstractThe main utilization mode of titano-magnetite was firstly separating titano-magnetite by low intensity magnetic separation, then concentrating ilmenite from magnetic separation tailings. Magnetic separation tailings mainly contained ilmenite, but there was still a small quantity of titano-magnetite. Magnetic agglomeration of titanomagnetite occured because of existentence of remanence and pre-flotation grinding. It was found that titanomagnetite presented more optimal floatability than ilmenite. Therefore some gangues wrapped by titano-magnetite went into the floatation concentrate. In a word, titano-magnetite had negative effect on ilmenite floatation by decreasing grade and recovery of concentrate and increasing reagent consumption. The pre-removal of residual titano-magnetite before cleaning ilmenite from magnetic separation tailings by floatation was essential

Deep Drawing of Cylindrical Cup Using Incremental Electromagnetic Assisted Stamping with Radial Magnetic Pressure

AbstractA new forming method named incremental electromagnetic assisted stamping with radial magnetic pressure is proposed to draw a deep cylindrical cup. The method combines with traditional stamping, electromagnetic sheet forming and electromagnetic launch technology. Three types of discharge coils are imbedded in die and blank holder, respectively. The 3D finite element model is set up to predict the complex deformation process. The forming process and principle of the new method are discussed. The values of material flow, stress and thickness in different forming processes are compared. In comparison with traditional stamping, incremental electromagnetic assisted stamping with radial magnetic pressure can significantly increase the value of material at sheet end flow inward, decrease the tensile stress and thickness reduction at the easily broken position, and obtain uniform stress distribution. Therefore, deeper cylindrical cup could be manufactured by incremental electromagnetic assisted stamping with radial magnetic pressure

Time Differential Pricing Model of Urban Rail Transit Considering Passenger Exchange Coefficient

Passenger exchange coefficient is a significant factor which has great impact on the pricing model of urban rail transit. This paper introduces passenger exchange coefficient into a bi-level programming model with time differential pricing for urban rail transit by analysing variation regularity of passenger flow characteristics. Meanwhile, exchange cost coefficient is also considered as a restrictive factor in the pricing model. The improved particle swarm optimisation algorithm (IPSO) was applied to solve the model, and simulation results show that the proposed improved pricing model can effectively realise stratification of fares for different time periods with different routes. Taking Line 2 and Line 8 of the Beijing rail transit network as an example, the simulation result shows that passenger flows of Line 2 and Line 8 in peak hours decreased by 9.94% and 19.48% and therefore increased by 32.23% and 44.96% in off-peak hours, respectively. The case study reveals that dispersing passenger flows by means of fare adjustment can effectively drop peak load and increase off-peak load. The time differential pricing model of urban rail transit proposed in this paper has great influences on dispersing passenger flow and ensures safety operation of urban rail transit. It is also a valuable reference for other metropolitan rail transit operating companies

Stability of the neutron-proton-electron matter under strong magnetic fields: the covariant Vlasov approach

The neutron-proton-electron(npe) matter under a strong magnetic field is studied in the context of the covariant Vlasov approach. We use a Walecka-type hadronic model and the dispersion relations for the longitudinal and transverse modes are obtained. The instability regions for longitudinal and transverse modes are also studied. The crust-core transition of a magnetized neutron star is discussed.Comment: 14pages, 4 figures, accepted for publication in PR