Reducing Perceived Urban Rail Transfer Time with Ordinal Logistic Regressions

In order to improve the transfers inside an Urban Rail Transit (URT) station between different rail transit lines, this research newly develops two Ordinal Logistic Regression (OLR) models to explore effective ways for saving the Perceived Transfer Time (PTT) of URT passengers, taking into account the difficulty of improving the transfer infrastructure. It is validated that the new OLR models are able to rationally explain probabilistically the correlations between PTT and its determinants. Moreover, the modelling analyses in this work have found that PTT will be effectively decreased if the severe transfer walking congestion is released to be acceptable. Furthermore, the congestion on the platform should be completely eliminated for the evident reduction of PTT. In addition, decreasing the actual transfer waiting time of the URT passengers to less than 5 minutes will obviously decrease PTT.</p

Bayesian network modeling explorations of strategies on reducing perceived transfer time for urban rail transit service improvement in different seasons

A new Bayesian Network (BN) learning approach is developed in this work to analyze the effect of different factors on the Perceived Transfer Time (PTT) of the Urban Rail Transit (URT) passengers. It is shown that the newly developed approach is able to build a BN with a satisfactory ability to assess effective strategies on reducing the PTT for the URT service improvement. Moreover, it is found that mainly determined by the weather, the relative environment inside an URT station plays the key role in deciding the impacts of varied factors on the PTT in different seasons. Fully illuminating the transfer passageway and preparing adequate and clear transfer guidance in an URT station are the most important in spring for the reduction of the PTT. Effectively decreasing the passenger flow conflicts in an URT station is the only way to evidently reduce the PTT in summer. Not only fully illuminated and well decorated transfer passageway but also increased train service frequency is indispensable to the decrease of the PTT in autumn. Besides minimizing the passenger flow conflicts, improving both frequency and time coordination of train services is essential for reducing the PTT in winter as well

Bayesian network modeling analyzes of perceived urban rail transfer time

This study proposes a Bayesian network (BN)-based approach to research the relationships between metro transfer perception time (MTPT) in different seasons and its influencing factors, and explores the strategies on reducing the MTPT for the improvement of the transfer experiences of passengers. Taking the city of China, Beijing, as the study area, the data related to the MTPT are collected in different seasons. Based on study data, BN modeling results indicate that factors affecting the MTPT in four seasons are not the same. The results of scenario analysis of BN demonstrate that the improvement of the transfer environment is effective for passengers in spring and autumn, while the passengers in summer pay more attention to the time and the space comfort of the walking stage of transfer. In addition, passengers in winter are concerned about the time and the space comfort of both walking and waiting stages of transfer

Optimizations of network layout and transport service frequencies in view of interests of transit line operators and utilizers

Layouts of bus networks in cities are always irrational currently, transport service frequencies also need to be optimized according to the real network layouts, operation conditions and travel experience of passengers, so it is essential to optimize bus transit network layouts and transport service frequencies systematically. Different stakeholders are involved in the optimization of urban bus transit network layouts like the government, operators and passengers, whose interests are always contradictory. In order to optimize transit network layout and service frequencies from the view point of operators and utilizers, this research constructs a multi-objective model and proposes a solution algorithm. The proposed multi-objective model is established from the perspective of operators with the goal of minimizing total operating costs for one day, and from the perspective of the utilizers to minimize the total travel time, respectively. Also with the application of electric bus in cities, buses in this research are electric buses all for green travel. Moreover, a solution algorithm is proposed in this research to solve the proposed multi-objective model with simulated annealing algorithm and genetic algorithm. Simulated annealing algorithm is used as the main framework of the solution algorithm from the perspective of operators to minimize operating costs, while genetic algorithm is used as the subroutine of simulated annealing algorithm to optimize total travel time. Verification of the proposed model and the solution algorithm is based on an intuitive network. The application results of a numerical experiment verified that the proposed optimization model and the solution algorithm are able to optimize the network layout and service frequencies at the same time

Research on the Contact Pressure Calculation Method for the Misaligned Elastomeric Journal Bearing

The pressure distribution of a misaligned elastomeric journal bearing is crucial for analyzing the uneven excessive wearing of the propulsion shaft bearing. However, analysis of the misaligned bearing is usually mainly based on the finite element method (FEM), which lacks a convenient and effective calculation method. This paper uses the influence coefficient factors (ICs) method to analyze the contact pressure of the misaligned bearing. First, the elastic displacement of the cylindrical shell subjected to a single point of concentrated force is derived and used to attain the new influence coefficient factors. Then, the geometric boundary conditions of planar conformal cylindrical contact are extended to the case of non-planar contact. Finally, the proposed method is applied and compared with other methods. The results show that the influence coefficient factors are greatly affected by the shape and constraints of the contact object. The proposed method is suitable for cylindrical shell contact analysis and has the same accuracy as FEM with half of the time consumption. In addition, the bearing capacity and contact stiffness are decreased as the effective contact area decreases due to misalignment

Frequency-shifted dynamics of Nd:YVO4 laser with anisotropic and quite weak optical feedback

The dynamic response of single-mode a-cut Nd:YVO4 laser combined with linearly polarized oscillation and orthogonally polarized optical feedback is investigated. Under frequency-shifted of 2 MHz, the output laser exhibits amplitude and phase modulation with anisotropic feedback when arbitrary retarder is inserted in external cavity. Its response characteristics vary with both phase retardation and optical axis orientation of the retarder. The amplitude response coefficient (ARC) and the phase response coefficient (PRC) are introduced to describe the response characteristics. In the special case where phase retardation equal to π/2, there is the minimum value in ARC and jump in PRC. Based on the Jones matrix of birefringent external cavity and rate equations of micro-chip laser, theoretical analysis of the frequency-shifted dynamics is carried out, in which the amplitude and phase response coefficient bridge the measurement and simulation quite well. Under different feedback level, the response limit of micro-chip laser with anisotropic feedback is verified as low as 10-9 of the reinjected light

Compositions, Structures, and Catalytic Activities of CeO₂@Cu₂O Nanocomposites Prepared by the Template-Assisted Method

CeO₂@Cu₂O nanocomposites were prepared from Cu₂O cubes and octahedra by the template-assisted method involving the liquid (Ce­(IV))–solid (Cu₂O) interfacial reaction. Their compositions, structures, and catalytic activities in CO oxidation were studied in detail. Under the same reaction conditions, CeO₂@Cu₂O nanocomposites prepared from cubic and octahedral Cu₂O templates exhibit different compositions and structures. With an increasing amount of Ce­(IV) reactant, a smooth CeO₂–CuO_<i>x</i> shell develops on the surface of Cu₂O cubes and eventually void cubic core/multishell Cu₂O/CeO₂–CuO_<i>x</i> nanocomposites form; however, a rough CeO₂–CuO_<i>x</i> shell develops on the surface of Cu₂O octahedra, and eventually hollow octahedral CeO₂–CuO_<i>x</i> nanocages form. The formation of different compositions and structures of CeO₂@Cu₂O nanocomposites was correlated with the different exposed crystal planes and surface reactivities of Cu₂O cubes and octahedra. The catalytic activity of CeO₂@Cu₂O nanocomposites in CO oxidation depends on their compositions and structures. The most active CeO₂@Cu₂O nanocomposites become active at 70 °C and achieve a 100% CO conversion at 170 °C. These results broaden the versatility of Cu₂O nanocrystals as the sacrificial template for the fabrication of novel nanocomposites with core/shell and hollow nanostructures and exemplify the morphology effect of Cu₂O nanocrystals in liquid–solid interfacial reactions with respect to the composition, structure, and properties of nanocomposites prepared by the template-assisted method