With the rapid economic development and urbanization process accelerating, motor vehicle ownership in large cities is increasing year by year; urban traffic congestion, parking difficulties, and other problems are becoming increasingly serious; in ordinary daily life, continuous risk of disturbance, having a flexible transportation system network is more able to alleviate daily congestion in the city, and the main thing about flexible transportation network is its algorithm. It is worth noting that congestion in many cities is generally reflected in the main roads, while many secondary roads and branch roads are underutilized, and the limited road resources in cities are not fully utilized. As an economic and effective road traffic management measure, one-way traffic can balance the spatial and temporal distribution of traffic pressure within the road network, make full use of the existing urban road network capacity, and solve the traffic congestion problem. Therefore, it is of great theoretical and practical significance to develop a reasonable and scientific one-way traffic scheme according to the characteristics of traffic operation in different regions. Based on the fixed demand model, the influence of traffic demand changes is further considered, the lower-level model is designed as an elastic demand traffic distribution model, the excess demand method is used to transform the elastic demand problem into an equivalent fixed demand problem based on the extended network, and the artificial bee colony algorithm based on risk perturbation is designed to solve the two-level planning model. The case study gives a one-way traffic organization optimization scheme that integrates three factors, namely, the average load degree overload limit of arterial roads, the detour coefficient, and the number of on-street parking spaces on feeder roads, and performs sensitivity analysis on the demand scaling factor.

Hongxiao Wang

Qiang Li

Sang-Bing Tsai

Network Design Algorithm Implementation for Resilient Transportation System under Continuous Risk Perturbation with Big Data Analysis

Electrostatic monitoring is a unique and rapid developing technique applied in the prognostics and health management of the tribological system based on electrostatic charging and sensing phenomenon. It has considerable advantages in condition monitoring of tribo-contacts with high sensitivity and resolution. Unfortunately, the monitoring result can be affected due to the switch of operating conditions that reduces its accuracy. This paper presents a dynamic adaptive fusion approach, moving window local outlier factor based on electrostatic features to overcome the influence. Life cycle experiments of rolling bearings and railcar gearbox were carried out on an electrostatic monitoring platform. The MWLOF method was used to extract and analyze the experimental data, combined with the Pauta criterion to judge wear faults quantitatively, and compare with other feature extraction results. It is verified that the proposed method can overcome the influence of changes in working conditions on the monitoring results, improve the monitoring sensitivity, and provide an accurate reference for friction and wear faults.

Ruochen Liu

Han Wang

Jinwu Zhang

Shuangshuang Gu

Jianzhong Sun

Research on Electrostatic Monitoring of Tribo-Contacts with Dynamic Adaptive Fusion Method

In the green supply chain approach, all the links that are put together to provide a product or service are considered, and strategic and operational decisions are made to increase the efficiency and effectiveness of the entire chain. At the same time, the environmental effects should be minimized. In this research, a nonlinear mixed-integer multiobjective model is developed to design a green closed-loop supply chain for medical products. In this supply chain, the echelons include supplier, manufacturer, warehouse, and customer in the forward supply chain and collection centers, repair services, and disposal centers in the reverse supply chain. In the proposed model, four objectives of customer satisfaction, environmental effects, supply risk, and total costs of the supply chain were considered. The developed model is implemented in a supply chain of medical products, and after optimizing the model, the main results including location and capacity of facilities, planning for flexible production, purchase of materials, service and maintenance plan, product transfer, and inventory level are determined and analyzed.

Reza Hazrati

Mohamad Samaei

Farkhondeh Mortaz Hejri

Shervin Haddad

Sajad Amiriyan

Designing a Medical Supply Chain Network Considering the Risk of Supply and Flexible Production in Two-Stage Uncertain Conditions

It is well known that the appearance of the delay in the fractional delay differential equation (FDDE) makes the convergence analysis very difficult. Dealing with the problem with the traditional reproducing kernel method (RKM) is very tricky. The feature of this paper is to gain a more credible approximate solution via fractional Taylor&#x2019;s series (FTS). We use the FTS to deal with the delay for improving the accuracy of the approximate solutions. Compared with other methods, the five numerical examples demonstrate the accuracy and efficiency of the proposed method in this paper.

Ming-Jing Du

A Specific Method for Solving Fractional Delay Differential Equation via Fraction Taylor&#x2019;s Series

The analysis of ship radiation signals to identify ships is an important research content of underwater acoustic signal processing. The traditional fast Fourier transform (FFT) is not suitable for analyzing non-stationary, non-Gaussian, and nonlinear signal processing. In order to realize the feature extraction and accurate classification of ship radiation signals with higher accuracy, a feature extraction method of ship radiation signals based on wavelet packet decomposition and energy entropy is proposed in this paper. According to wavelet packet decomposition, the ship radiation signal is decomposed into different frequency bands, and its energy entropy feature is extracted. As for comparisons, the center frequency and permutation entropy are also used as features to be extracted, then the k-nearest neighbor is applied to classify and recognize the extracted results. Based on the comparisons of wavelet packet decomposition, the center frequency, permutation entropy, and the k-nearest neighbor are used for classification and recognition. The experimental results present that, when comparing with center frequency and permutation entropy, the method based on energy entropy has the best availability, with the highest average recognition rate for four types of ship radiation signals, up to 98&#x0025;.

Yuxing Li

Feiyue Ning

Xinru Jiang

Yingmin Yi

Feature Extraction of Ship Radiation Signals Based on Wavelet Packet Decomposition and Energy Entropy

This paper presents an improved internal model control system to raise the efficiency of refining low-carbon ferrochrome. This control system comprises of a piecewise linearized transfer function and an improved internal model controller based on optimized time constant of the filter. The control system is mainly used to control the oxygen supply rate during the argon-oxygen refining for controlling the smelting temperature. The regulatory performance and servo of two closed-loop control schemes are compared between the improved internal model controller based on the optimized filter time 0000-0002-7606-6546and the internal model controller based on the fixed filter time constant. The simulation analysis shows that the piecewise linearized model and the optimization of the time constant of the filter improves the response time, stability, and anti-interference ability of the controller. Then, the proposed improved internal model controller is used to adjust the gas supply flow in 5 ton AOD furnace to control the smelting temperature. Ten production tests performed the effectiveness of the controlling refining optimal system. The analysis of the experimental data shows that the improved internal model control system can shorten the melting time and improve the melting efficiency. Thus, the application of the improved internal model control system in low-carbon ferrochrome refining is an interesting potential direction for future research.

Changjun Guan

Wen You

Optimal System for Improved Internal Model Control of Argon-Oxygen Decarburization Process Based on the Piecewise Linear Model and Time Constant of Filter Optimization

With the accelerating process of economic globalization, the deep adjustment of the international industrial division of labor, and the continuous upgrading of the global value chain, the development of the service industry has entered into a new historical period. This study analyzes the dynamic evolution of trade network structure at three levels: macro, mesa, and micro, and empirically explores its influencing factors. Taking national service trade as the research object, this study analyzes the topological structural characteristics of the food trade network of &#x201C;One Belt and One Road&#x201D; countries by selecting indicators such as network point degree, average path length, trade intensity, intermediation degree, and aggregation coefficient, and further explores the characteristics of association network structure in national service trade network using block model. The topological structural characteristics of the &#x201c;Belt and Road&#x201d; trade network are analyzed from three aspects: overall, local, and individual. Then, we construct a regression model to analyze the factors influencing the dynamic evolution of the service trade network structure of the countries along the &#x201c;Belt and Road&#x201d; through the QAP method. Finally, based on the summary of the research findings, this study puts forward the corresponding considerations and policy recommendations from the perspectives of regional, directional, and reciprocal investment, to benefit more efficient and strategic national service trade under the framework of &#x201C;Belt and Road.&#x201D; Based on the results of this study, this study proposes the following policy recommendations: firstly, actively promote the service trade cooperation with other countries to optimize the market layout; secondly, promote the service industry reform to extend the length of the value chain and improve its position in the value chain; and thirdly, jointly promote the infrastructure construction of &#x201C;Belt and Road&#x201D; with other countries, promote trade liberalization, and reduce the trade volume. Secondly, we should promote the reform of the service industry, extend the length of the value chain, and improve our position in the value chain. Finally, we should vigorously promote the development of innovation, promote the two-way opening of new service industries, adhere to the &#x201c;going out&#x201d; strategy, and cultivate high-quality and excellent technical talents, to promote the overall improvement of the innovation-driven capacity of the service industry with a people-oriented approach.

Yang Liu

Dynamic Evolution of Service Trade Network Structure and Influence Mechanism in Countries along the &#x201c;Belt and Road&#x201d; with Big Data Analysis

Bichang Huang

Dan Luo

Wenxing Zhu

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Mathematical Problems in Engineering is a broad-based journal publishing&nbsp;results of rigorous engineering research across all disciplines, carried out using mathematical tools.

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Chief Editor, Professor Guangming Xie, is currently a full professor of dynamics and control with the College of Engineering, Peking University. His research interests include complex system dynamics and control and intelligent and biomimetic robots.

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Mathematical Problems in Engineering