A Fast Diagnosis Method of Escalator Reversal Faults Based on Dynamic Information and Multiattribute Decision-Making

There are many reasons for escalator reversal failure, and the reasons are distributed in different locations. It is difficult to locate the specific location of the fault in the actual fault troubleshooting. At the same time, the information related to the failure is not used in the troubleshooting, so there is a problem of inefficient troubleshooting. To this end, this paper proposes a multiattribute decision-making method that integrates dynamic information and gives the optimal troubleshooting order to improve the efficiency of the troubleshooting. First of all, according to the structure of the escalator components, the escalator reversal fault tree is established. Secondly, a static decision matrix is established by comprehensively considering the failure probability, search cost, and influence degree of the bottom event of the fault tree. Finally, the influence matrix of information on each attribute is given by the dynamic information obtained in troubleshooting, the static decision fusion influence matrix determines the dynamic decision matrix, the dynamic decision matrix is weighted and normalized, and the Technique for Order Preference by Similarity to Ideal Solution is used to determine the optimal troubleshooting order. Taking the reversal failure of a certain type of escalators as an example, the method of multiattribute decision-making of fusion dynamic information is used to shorten the troubleshooting time, improve the efficiency of troubleshooting, and verify the effectiveness of this method.

Evaluation of Emergency Rescue Efficiency in Coal Mines Based on Co-entropy

By decomposing the coal mine emergency rescue organization and coal mine emergency rescue work, the synergy entropy function is constructed by combining the synergy class with the entropy theory, and the synergy efficiency assessment model of coal mine emergency rescue is established. Analyze the synergistic relationship between departments in the rescue organization and between departments and functional units, construct the synergistic influence matrix, and obtain the synergistic status of the coal mine emergency rescue system by calculating the synergistic entropy, synergistic efficiency and synergistic degree. The quantitative analysis of the emergency rescue system in coal mines is achieved by analyzing the situation of the rescue work in coal mines and evaluating the rescue organizations at each tier based on the established evaluation model.

Damage Identification in Hangers of Through-Arch Bridges Using Static Deflection Difference at the Anchorage Point

This study proposes a new damage identification method for hangers of arch bridges using the static deflection difference at the anchorage point of the hanger and the tie-beam. The relationship between the ratio of cable tension loss and the deflection difference at the anchorage point is studied. For the first time, the deflection difference influence matrix for hanger damage identification is defined. The static deflection change parameter is formulated as a function of the deflection difference influence matrix and the ratio of cable tension loss. The study shows that the percentage of cable tension loss can be obtained from the changes in static deflection at the anchorage point and the deflection difference influence matrix. Therefore, by observing a plot of the ratio of cable tension loss, the damage locations can be identified conveniently. Numerical and laboratory studies show that this method can accurately locate the damaged hanger of through-arch bridges under various scenarios. The proposed damage detection method has a clear theoretical base and is simple to operate, and it is suitable for practical engineering.

Generation of Tri-Directional Spectra-Compatible Time Histories Coupling the Influence Matrix Method and Gram–Schmidt Orthogonalization

This study presents a new approach for obtaining a set of tri-directional time histories compatible with target design spectra by modifying real recorded earthquake ground motions. The influence matrix method (IMM) based on eigenfunction expansion is improved for typical design response spectra with different shapes and employed in order to achieve accurate matching with the target design spectra. By applying the Gram–Schmidt orthogonalization in each iteration of the IMM procedure, the correlation coefficient between any two components can be guaranteed to be strictly zero. Hence, the generated three components in the orthogonal directions are statistically independent. The generated time histories satisfy the requirements of current codes and standards. Two examples are presented to illustrate the procedure and the superiority of the proposed method, with the maximum relative error between the generated time histories and target design spectra being less than 0.2% in [0.6, 100] Hz, and the code requirements being satisfied strictly.

Matrix condition mitigates the effects of habitat fragmentation on species extinction risk

Habitat loss is the leading cause of global biodiversity decline, but the influence of human pressure within the matrix surrounding habitat fragments remains poorly understood. Here we measure the relationship between fragmentation, matrix condition (measured as the extent of high human footprint levels), and the change in extinction risk of 4,327 terrestrial mammals. We find that the matrix condition and the fragmentation of habitat are strongly associated with changes in species extinction risk. Importantly, we discover that fragmentation is a stronger predictor of risk than species life-history traits, habitat loss, and habitat amount. Moreover, the importance of fragmentation increases with an increasing deterioration of the matrix condition, highlighting the critical influence matrix quality plays on the effects of fragmentation. These findings suggest that restoration measures in habitat matrices may be an important conservation action for mitigating the effects of fragmentation relative to extinction risk of terrestrial mammals.

Mathematical Development of a Novel Discrete Hip Deformation Algorithm for the In Silico Elasto-Hydrodynamic Lubrication Modelling of Total Hip Replacements

In this paper, the procedure to achieve an accurate deformation model of a total hip replacement (THR) was proposed with the aim to obtain a numerical tool to be simply merged into THR elasto-hydrodynamic computational synovial lubrication algorithms. The approach was based on the Finite Element Method (FEM) and was developed in a Matlab code, allowing the definition of the influence matrix and of a boundary conditions vector. It works with linear tetrahedra and performs the displacement calculation for both the acetabular cup and the femoral head, taking into account the anatomical hip relative motion, by coupling them with a cubic interpolation matrix. Two simulations were conducted in order to validate the algorithm and the results were compared with the ones obtained by the commercial software Ansys. The comparison provides a satisfactory agreement in terms of surface deformation, Von Mises stress and strain energy, proving the reliability of the model and the possibility to use the model in the in silico prostheses tribological simulations, avoiding the complexity and the high computational resource requirement coming from the coupling between complex lubrication algorithms and FEM commercial software, and with the possibility to directly act on many key parameter characteristics of the investigated problem.

Research of Indicators of the Internal and External Environment Influencing the Implementation of the Demand Management System (Demand Side Management) in the Russian Industry

The relevance of the presented research is determined by the need of the Russian economy for the implementation of advanced methods for improving energy efficiency, one of which is the demand management system for electricity and gas consumption. The objective of the article is to identify a set of macro environmental factors that have a limiting effect on the implementation of an integrated demand management system for the consumption of electricity and natural gas in the Russian economy. The research methods are methods of analysis, synthesis and analytical grouping. On the basis of the PESTEL-analysis, the author carried out a classification of the entire spectrum of factors into six categories: political, economic, socio-cultural, technological, environmental and legal. For each factor the degree of influence on the project of introducing a demand management system was determined on the basis of four signs of degree of importance. According to the influence matrix, all the factors were ranked by degree of influence and probability of occurrence and were prioritized as high, medium and low. For the factors of high and medium priority, a complex of preemptive actions was developed, including administrative control, regulatory and innovative measures. The identified factors, as well as their detailed analysis and classification, form the basis for the development of methodological support for an integrated demand management model for electricity and gas consumption in Russia.

Formation of Moments Influence Matrix in Frame Based on Graph of its Design Scheme

A procedure is proposed for the automated construction of the bending moments influence matrix in the frame based on the graph of its discrete model. Forming the incidence matrix of the graph characterizing the topological structure of the design scheme of the frame, through matrix transformations of the displacement vectors, at the transition from local coordinate systems to a global system, it is possible to establish the relationship between the nodal displacements and the displacement increments of individual sections in the direction of the axis of the segment and perpendicular to it. The composition of only three initial matrices of the frame structure, the incidence matrix of the graph, the node coordinate matrix and the matrix of the frame model internal rigidity, solves the problem of automatic formation of the bending moments influence matrix with the help of a PC. The procedure proposed for the construction of the influence matrix, makes it possible to find the forces in the frame structure caused by external load, in the matrix form.

On the linkage between influence matrices in the BIEM and BEM to explain the mechanism of degenerate scale for a circular domain

ABSTRACT In this paper, we proposed two ways to understand the rank deficiency in the continuous system (boundary integral equation method, BIEM) and discrete system (boundary element method, BEM) for a circular case. The infinite-dimensional degree of freedom for the continuous system can be reduced to finite-dimensional space using the generalized Fourier coordinates. The property of the second-order tensor for the influence matrix under different observers is also examined. On the other hand, the discrete system in the BEM can be analytically studied, thanks to the spectral property of circulant matrix. We adopt the circulant matrix of odd dimension, (2N + 1) by (2N + 1), instead of the previous even one of 2N by 2N to connect the continuous system by using the Fourier bases. Finally, the linkage of influence matrix in the continuous system (BIE) and discrete system (BEM) is constructed. The equivalence of the influence matrix derived by using the generalized coordinates and the circulant matrix are proved by using the eigen systems (eigenvalue and eigenvector). The mechanism of degenerate scale for a circular domain can be analytically explained in the discrete system.