Transport Operations Research Articles

Aggregator-supported strategy for electric bus fleet charging: A hierarchical optimisation approach

The increasing adoption of electric buses in cities presents an opportunity for these vehicles to serve as mobile energy storage systems, providing valuable grid services through their substantial battery capacity. However, the complex interplay of fleet management and energy market participation requires that public transportation operators (PTOs) use adequate optimisation models and algorithms to make the best operational decisions. To address these issues, our research proposes an aggregator-supported charging strategy using a bi-level optimisation framework for electric bus fleets. The main goal is to achieve a balance between reducing PTO operational costs and maximising aggregator revenues, while ensuring reliable bus system operation. The results indicate that a coordinated charging strategy, including energy arbitrage and reserve provision, can significantly reduce operational costs, although potential limitations arise from associated battery degradation costs. Furthermore, managing fleets for reserve services appears to be more lucrative than engaging in energy arbitrage schemes. In this context, this study emphasizes the role of aggregator entities in managing the energy flexibility of electric bus fleets and enhancing the sustainability and cost-effectiveness of urban public transportation.

Research on the Dual-Objective Scheduling of the Pipeline Path of Liquid Terminal Resources Based on a Hybrid Algorithm

With the daily use of liquid cargoes such as crude oil and their derivatives, the global transportation of liquid cargoes has developed rapidly. Liquid cargoes are mainly transported via tankers and pipelines. In the liquid terminal, the handling operations and internal transportation operations are conducted using oil transfer arms and pipelines, and the pipeline path of the cargo is selected using valves. The number of times a valve opens and closes and the length of pipeline paths are the main factors that affect handling time and cost. In addition, different types of valves have different operating costs and levels of operating energy consumption. At this stage, most of the valve selection work is still manually completed, which consumes a lot of time and generates high labor costs, and the actual operation efficiency is low. In this paper, the cargo unloading pipeline path is the main research object, the problem of oil transfer arms–valves–pipeline (PAVP) is proposed, and a dual-objective model is established, accounting for total time in port and the unloading cost of the vessel. An NSGA-II-Dijkstra hybrid algorithm is employed to solve the PAVP, and the improved algorithm (INIIDA) is designed to improve the solution speed via an adaptive dynamic probability based on the Pareto level and heaps in the shortest path. The results show that the INIIDA could better address the PAVP than the NSGA-II-Dijkstra hybrid algorithm. Innovative fusion algorithms are employed to improve the efficiency of port operations.

Research on Carbon Emission Pre-Assessment of Residential Buildings in Xi’an City during the Scheme Design Stage

The effect of energy saving and carbon reduction in the building industry is closely related to the realization of China’s double carbon goal. In this study, a two-dimensional framework for building life cycle carbon emissions was established, which takes into account the early stages of building design such as the feasibility study stage and scheme design stage. Taking 57 residential buildings in Xi’an City as examples, the life cycle carbon emission characteristics of residential buildings in cold areas were introduced. This study found that the life cycle carbon emission intensity is about 45~55 kgCO2/(m2·a). The operation and maintenance stage and building materials production stage accounted for the largest proportion of carbon emissions, and the sum of carbon emissions of the two stages accounted for 92.3% of the total carbon emissions. In addition, based on the probability density function, the carbon emission intensity distributions of the building life cycle, building material production stage, building material transportation stage, and operation and maintenance stage were analyzed, and it was found that each distribution fitting graph was generally in line with a lognormal distribution, and their expected value provided a reference index for carbon emission pre-assessment in the feasibility study stage. Based on the analysis and determination of 11 independent variables that affect the total carbon emissions, such as area, floor number, story height, and number of households, a multiple linear regression model for carbon emission pre-assessment in the design stage of building schemes is proposed. The R2adj of the model is 0.985 and the error is about 10%. The prediction model can provide beneficial guidance for the life cycle carbon emission prediction in the design stage of building projects, so as to reduce carbon emissions by changing building design.

Quality of public transport services in Chisinau

The quality of transport services represents the most comprehensive and synthetic attribute that reflects the performance of a transport system. In the public transport system, the quality of service is largely influenced by the way passengers perceive its performance. The quality of transport services is assessed according to a number of technical and economic indicators that characterize the performance of transport operators within the framework of the urban public transport system. The article aims to identify the criteria for evaluating the quality of urban public transport services based on the study carried out for the public transport system of the municipality of Chisinau and to describe the indicators that reflect the performance offered by the public transport system, as perceived by passengers. It should be noted that the quality of the urban public transport service has a direct impact on the quality of life of all city residents. The study includes a concrete survey of the beneficiaries of public transport in the municipality of Chisinau, which analyzes the quality criteria and their rate of appreciation by the inhabitants of the municipality. Finally, conclusions and future directions of action aimed at improving the quality of services and increasing the attractiveness of urban public transport are presented, thus contributing to the improvement of the quality of life of the inhabitants.

Підвищення ефективності забезпечення працездатності транспортних засобів

Accidental failures, leading to unplanned repairs, significantly increase the cost of their elimination compared to planned measures. A significant part of such failures are not sudden in nature. Gradual failure is preceded by a gradual change in some parameters. The impact of gradual failures on the efficient operation of road freight transport is increasing. Despite the fact that the failure of the engine, clutch or automatic transmission is not dangerous to the life and health of people, their impact on the economic condition of the enterprise is significant. There is a trend of decreasing the size of the rolling stock fleet for most of the country's motor transport enterprises. Therefore, the importance of keeping each car in working condition increases. To increase the accuracy of the prevention of gradual and sudden-gradual failures, a forecasting method based on the diagnosis of trucks with a specialized diagnostic car scanner TEXA Navigator MULTIHUB is proposed. The selection of diagnostic parameters was carried out in accordance with the requirements for compliance with the accuracy, efficiency, and informativeness of the diagnostic parameters. The research was carried out on MAN TG-X, MAN TGA, VOLVO FH 12, DAF 105 XF, and DAF 106 cars. A sequential cylinder shutdown test was conducted to determine the compression and efficiency of all cylinders. A gradual change in the operating parameter is determined based on the obtained decrease in revolutions. In the next test, the correction of the injectors for the amount of fuel injected into the cylinders is checked. The reference value is taken as 0. The correction tolerance for increasing or decreasing the fuel supply time should be within +1 or –1. Based on the received data, the nozzle is determined, in the correction gradually increases, which signals a problem with the nozzle's operation. For the clutch, a test of the position of the start of switching on and off was carried out. By reducing the percentage of idling, you can determine the gradual engagement of the clutch. All the conducted tests make it possible to graphically display a change in a parameter or property and, using extrapolation, to predict the moment of failure. All cars carry out freight transportation in international traffic. Control parameters and data extrapolation made it possible to predict engine, clutch, and automatic transmission failures. Selected diagnostic parameters can be used to predict and prevent failures.

Дослідження процесу перевезення пасажирів з моделюванням роботи зупинок громадського транспорту

Public transport is characterized by its accessibility and sharing and is intended for a wide range of people, regardless of social status or income. The main function is to provide the ability to move people from one place to another within the city. Bus stops are a strategic place to ensure territorial accessibility from central to peripheral neighborhoods. They maintain order and organization in the operation of public transport. It is the study of the network of public transport routes and stops that is crucial for improving the quality of service, increasing the efficiency of transport systems and ensuring convenience for users. However, in each case, it is necessary to use an individual approach to organizational and planning decisions. The article describes the peculiarities of the functioning of public transport in the city of Dubno, Rivne region, in the context of research on infrastructure, route network, passenger flow, location and modeling of stops, taking into account the future development of new neighborhoods. It was found that the route network in Dubno includes 22 public transport routes with 64 stops. On average, 19544 passengers use public transport and get off at bus stops every day - 54% of all city residents. The rapid development of the city requires the arrangement of new public transport stops with changing routes, the operation of which in the overall transportation system was investigated by simulation modeling. The results obtained will make it possible to develop schedules and routes for public transport and to perform technical and economic calculations for the modern arrangement of stops. The research reported in this article was conducted at the National University of Water and Environmental Engineering with the support of the Department of Economics and Property of the Dubno City Council.

Characterization of Several Pellets from Agroforestry Residues: A Comparative Analysis of Physical and Energy Efficiency

The use of agroforestry biomass provides several advantages, both from an environmental point of view, in terms of the mitigation of global warming, and in terms of a circular economy for agricultural or agroforestry companies that reuse pruning residues as a source of energy. However, even if the use of energy pellets resulting from the pruning residues of various agroforestry species has excellent potential for the valorization of agricultural by-products, the physicochemical characteristics of these pellets have been scarcely studied by the scientific community. In this context, this study aims to assess the valorization potential of various lignocellulosic material residues produced during agroforestry activities. The objectives of the study include evaluating the chemical and physical characteristics of pellets produced with different mixtures of agroforestry biomass (olive, citrus, black locust, poplar, paulownia, etc.) in order to determine the optimal pellet blend from an energy and physicochemical perspective. The results of this study demonstrate that this comprehensive analysis provides valuable information on the optimization of biomass mixtures for better energy valorization, addressing both compositional and combustion-related challenges. In fact, it is observed that the addition of citrus and olive biomass to the various mixtures increases their energy potential. Furthermore, all of the pellets analyzed are found to possess an adequate and useful durability index (PDI) for their handling during storage and transport operations. This study demonstrates that olive and citrus pruning residues can be used to improve biomasses that have poor suitability in energetic, physical, and chemical terms. Further studies could be useful to understand which specific interaction mechanisms have an influence on emissions in order to optimize mixtures using different biomass sources for sustainable energy production.

Сравнение годовых грузооборотов железнодорожного и автомобильного транспортов РФ: моделирование, верификация, точечный и интервальный прогноз

Purpose: a study was conducted comparing the freight turnover of rail and road transport in the Russian Federation over the last twenty years and a forecast assessment was made. The comparative assessment was carried out due to the excess of freight turnover by rail over road transport. The study includes the following main stages: modeling based on the observed annual values of cargo turnover; model verification by comparing model and experimental values in years not involved in the construction of the model; model point and interval forecasting; analysis of the forecast trend of changes. The mathematical model of the excess of freight turnover by rail over road transport from the year of cargo delivery is based on a sample of statistical data from Rosstat from 2004 to 2021. The model was verified based on the results of cargo turnover in 2022 and 2023. Methods: to build a mathematical model, test it and carry out forecasting, a number of theoretical provisions of econometrics were used, including dynamic series, regression analysis, the least squares method, point and interval forecasting. The applied calculation apparatus was used using the Excel PPP. Results: the quality of the constructed model was evaluated by the following indicators: approximation errors, correlation and determination coefficients, and the Fisher criterion. A comparison of the observed and model values of excess cargo turnover showed that in the period from 2004 to 2021, according to the above indicators, they have minor deviations. The verification performed confirmed the satisfactory simulation. Practical significance: the conducted research has shown that it is possible to predict the results of transport operations according to the described algorithm and it is justified to make management decisions at the beginning of their implementation. Recommendations: to continue improving the modeling and forecasting apparatus, taking into account the assessment of risk indicators.

Peningkatan Okupansi Penumpang Lrt Sumatera Selatan Dengan Menganalisis Penumpang Integrasi Lrt Sumsel

For more than five years of operation, the South Sumatra light train (LRT) occupancy rate has not yet reached the target, so it is necessary to evaluate the program and realize the costs per passenger for South Sumatra LRT transport operators. The implementation methods that will be carried out at the completion of the research are the preparation stage, data collection, analysis and document preparation, evaluation and assistance, and refinement. This results in macro and micro costs for operating the South Sumatra LRT pilot.

CONCENTRATION OF LUNAR PLAGIOCLASE FOR SOLAR CELLS FABRICATION. AN ISRU CONCEPTUAL ARCHITECTURE

Solar panels are required on the Moon to provide power for human activities, especially mining and civil operations. To provide enough power and maintain human settlements working, a technical solution known as the Tall Lunar Tower (TLT) claims to be able to capture sunlight 93% of the time through solar panel structures and provide 50 kW per tower. A typical photovoltaic panel is made of 76% glass, 10% polymer, 8% aluminum, 5% silicon, and 1% other metals. Delivering these materials from Earth is expensive and risky. Fortunately, lunar regolith contains large amounts of silicon and aluminum oxides and silicates, thus, it would be feasible to use the resources in situ for metal production, hence, we just need to transport polymers, wire, and minor components from Earth. This article presents an ISRU (in-situ resource utilization) architecture to provide plagioclase concentrate, the economic lunar ore for aluminum and silicon extraction. The document details engineering aspects and technological solutions for lunar mining, including excavation, transport, and beneficiation operations; based on a hypothetical construction and deployment of TLT at the South Pole. Processing techniques such as screening and magnetic separation are discussed to evaluate their advantages and drawbacks to obtain an expected plagioclase concentration of 70% grade with 18% recovery. Finally, an outline of recommendations for industrial manufacture is discussed, considering the sequential lunar metals extraction and the quality required.

Understanding the Competition and Cooperation between Dockless Bike-Sharing and Metro Systems in View of Mobility

The advent of dockless bike-sharing (DBS) represents an effective solution to enhance public transportation usage. However, despite growing interest in integrating DBS with metro systems, comprehensive studies on their competitive and cooperative relationships remain limited. This study aims to analyze the spatial, temporal, and mobility characteristics of metro-related DBS to explore integration opportunities. Initially, three modes of interaction between DBS and metros are identified: strong competition, weak competition, and feeder relationships. Subsequently, based on these relationships, the analysis focuses on distance, spatio-temporal patterns, and the scope of DBS activities. Results from Beijing indicate that metro-associated DBS primarily serves as “last-mile” solutions without significant short-range competition with metro systems. Strongly competitive relationships, on the other hand, are interaction patterns due to the dense overlay of metro stations and inconvenient transfer facilities and are mainly used for non-commuting purposes. Furthermore, weakly competing and feeder DBS systems exhibit similar commuting patterns, highlighting bicycling as a viable alternative to walking within metro catchment areas and that metro catchment areas should be adapted to bicycling. Mobility communities, identified as tightly integrated cycling hubs, are proposed as strategic dispatch zones to manage peak demands and reduce operational strain on DBS fleets. These findings deepen our understanding of DBS and metro system interactions, offering insights to optimize public transport operations and enhance urban mobility solutions.

ORGANIZATIONAL AND TAX ASPECTS OF THE FREIGHT FORWARDING ACTIVITIES IN BULGARIA

Svetoslav Iliychovski E-mail: s.iliychovski@uni-svishtov.bg Assoc. Prof. PhD, DA Tsenov Academy of Economics Svishtov, Bulgaria https://orcid.org/0000-0001-9947-8650 Teodora Filipova E-mail: t.filipova@uni-svishtov.bg Assoc. Prof. PhD, DA Tsenov Academy of Economics Svishtov, Bulgaria https://orcid.org/0000-0001-6584-5846 Abstract: The research is aimed at a specific sub-sector of the economy, with importance for the development of many business ventures. Knowledge of the main regulatory documents, the essence, the place and the role of forwarding in the company's processes is a leading factor for the accurate, reliable, timely and high-quality implementation of logistics. Freight forwarders act as intermediaries between consignors and transport operators when transporting goods between different countries. They organize all stages of the transport process and can also carry out the transport themselves. When sending goods on different routes, the participation of one or more carriers may be necessary, in addition, different requirements and conditions are imposed for the execution of the transaction. Forwarding services are intended to provide and coordinate the entire process of preparing and carrying out shipments in order to satisfy customer requirements. The aim is to analyze the main organizational aspects and the peculiarities of the taxation of forwarding activity in Bulgaria on the basis of theoretical studies and practical results. A historical approach, methods of synthesis, analysis and comparison are used. The time period is 2020, 2021, 2022. The leading thirty companies in the industry were analyzed, and results were compared based on revenue and dynamics of change. The regulations of the Commercial Law, tax and accounting acts have been interpreted. Basic schemes for organizing freight forwarding activities and features of taxation are commented on. On the basis of literary sources, official databases and own summaries, the main hypothesis has been proven, namely: the correct forecasting of the factors that influence the activity of forwarding companies and the choice of flexible solutions are a prerequisite for successful commercial activity. Keywords: freight forwarder, forwarding contract, transport, taxation., JEL classification: L91

Integrated scheduling of multi-constraint open shop and vehicle routing: Mathematical model and learning-driven brain storm optimization algorithm

Recent years have witnessed a surge of interest in integrated production and distribution scheduling problems which can achieve an overall optimization of the production and distribution activities. However, integrated scheduling of open shop and distribution receives rare attention in existing studies. This work proposes an integrated scheduling problem of multi-constraint open shop and vehicle routing to minimize maximum completion time, where group and transportation operations are considered together in the production process. All jobs are divided into multiple groups, and then handled in an open shop with multiple machines. Subsequently, the jobs are delivered to their corresponding customers. First, a mixed integer programming model is formulated to define the problem. Second, a Q-learning-driven brain storm optimization algorithm is developed to address the formulated model. A Q-learning method is employed to choose search strategies for generating new individuals rather than using fixed probability parameters straightforwardly as basic brain storm optimizers. In addition, the solution encoding, heuristic decoding, population initialization, clustering, new individual generation and selection methods are specially devised in consideration of problem-specific knowledge. At last, the developed model and algorithm are verified by addressing a set of benchmark instances, and comparison experiments are conducted with an exact solver CPLEX and four meta-heuristics from existing literature. The results validate the competitive advantages of the formulated model and algorithm in solving the considered problems.

MobileNetV2 with Spatial Attention module for traffic congestion recognition in surveillance images

Traffic congestion recognition is essential for road traffic condition monitoring and improving transportation operation efficiency. Recent works have proposed using computer vision to develop cost-effective traffic congestion detection systems. This paper proposed a custom framework for recognizing traffic congestion using a trained advanced CNNs model on highway surveillance images. The proposed CNNs model uses an attention mechanism that significantly helps the network performing better. Specifically, a spatial attention module is proposed to aggregate model features and increase representational power. Exploring the optimal model choice for edge device deployment: MobileNetV2 is considered the best model choice for this task due to its lowest FLOPs and params. Furthermore, the accuracy of MobileNetV2 with attention module on the test set exceeds that of several advanced CNNs models such as VGG16, GoogLeNet, ResNet50, Efficientnetb0, DenseNet121. For a selected dataset of real-world traffic congestion images, test accuracy of 98.58% strongly supports the model’s efficiency in recognizing traffic congestion rendering image samples. In addition, proposed model also achieves 98.82% on the UCSD dataset, which as same as sort-of-the-art method. In summary, we have developed a congestion detection framework equipped with spatial attention module. Extensive experimental validation has demonstrated that using MobileNetV2 as the backbone network achieves state-of-the-art performance. The framework also uses the Grad-CAM approach for visual interpretability and localization of traffic congestion in surveillance images. Judging from the results of Grad-CAM, attention-integrated models can localize traffic congestion in surveillance images better. Our model is developed under the Pytorch framework using python3.8.

A generalized integrated framework for urban public transport operations evaluation based on interval neutrosophic TODIM and EDAS technique

A generalized integrated framework for urban public transport operations evaluation based on interval neutrosophic TODIM and EDAS technique

ORGANIZATION OF DELIVERY OF THE COMPANY'S PRODUCTS BY OWN VEHICLES

Purpose. The purpose of the work is the formation and analysis of options for the organization of the delivery of the machine-building enterprise's products by its own vehicles. Methodology. The main stages of choosing a rational technology for the organization of product transportation by own transport based on the developed schedules have been formed. The research was performed on the basis of the analysis of graphs of the dependence of motor vehicle operation indicators on the technology of organizing the transportation of the company's products. Findings. The article develops and analyzes work schedules for the delivery of the company's products by tractor-trailer trucks with semi-trailers. According to the schedules, the duration of delivery of one product in a ready-to-install condition to the consignee, the maximum possible annual volumes of transportation, the maximum and actual average annual operating costs for the delivery of the company's products by its own vehicles are determined. Practical value. The results of the research can be used to make a decision on the expediency of refusing the services of logistics companies to organize the delivery of the company's products to customers.

Transport and mining machinery cabins’ ergonomic evaluation as a path to its redesign

Transport and mining machinery cabins are still not well adapted to their users, while checklists for their evaluation are not common in the literature. This article proposes a new checklist for ergonomic evaluation and tests its universality empirically with a sample of 96 transport and mining machine operators. The objective of the article is two-fold. First, the article checks whether there are anthropometric dimension differences between different machines’ operators. Second, statistical significance testing regarding items in the proposed checklist is performed to check its universality. Significant differences have not been found between anthropometric dimensions of transport and mining machine operators. Group comparisons prove that mining machines have better ergonomics characteristics of the chair, manual controls and vision field. The recommendation for crane designers is to examine mining machines solutions and analyze the possibility of adapting these solutions, due to anthropometric fit. Wide usage of the checklist is recommended.

Secure Travel Planning Using a Heuristic Algorithm

Security perception in the urban area has a significant effect on travel behaviour, preferences, and tour planning. The perceptions of security risks can vary depending on factors, such as age, gender, and previous experiences. This study aims to consider security risks when developing travel plans and schedules for various activities. An improved heuristic algorithm, based on the Travelling Salesman Problem with security parameter and flexibility aspects, is proposed. Public transport is considered in three situations: fixed, flexible, and flexible-security situations. The outcomes demonstrate that the flexible situation significantly decreases travel times by 21% compared to the basic (fixed) situation. At the same time, with a slightly increased travel time the security risk can be avoided in the flexible-security situation. Travelers can enjoy a higher quality of travelling and enhanced personal experience by minimizing the journey duration and the impact of security risks on the tour schedule. The proposed method provides significant benefits for transport operators by increasing the efficiency of the transportation system and higher customer satisfaction.

Dynamic analysis of a hydraulic motor lifting auxiliary beam of monorail crane

Abstract Monorail crane that is an important class of auxiliary transportation equipment in coal mine. It works on a single hanging track fixed above the coal mine roadway to transport materials, machines, people, etc. Lifting auxiliary beam is the main part of the lifting beam which is used to complete the lifting and transport operations. In the application process, the lifting auxiliary beam is bore many types of loads such as discontinuous loading, frequent starting and braking etc. It complicates the dynamic performance that directly affects the safety and the lifting operation stability. By using finite element method, a dynamic model of the lifting auxiliary beam is established to study the variation laws of dynamic load, frequency, amplitude, etc. Furthermore, three loading conditions are defined in the model. They are static loading, slow loading and fast loading, considering the lifting operation time. The numerical simulation results show that the maximum displacement of the fast loading condition is 20% to 23% higher than that under the static loading condition. Moreover, under the fast loading condition, the largest displacement amplitude occurs in the middle part of the lifting auxiliary beam and it decreases gradually towards the ends.

Collective or Individual? Tourists’ travel mode choice during a pandemic

The coronavirus pandemic (COVID-19) led to holiday journeys being associated with significant health risks. While there are numerous studies on the impacts of the COVID-19 pandemic on travel mode choice in everyday mobility, there are a lack of studies on tourists’ choice of travel mode, even though tourism transport in Switzerland makes up 24% of all distance travelled. Based on an extended conceptual framework of the Health Belief Model (HBM), this study investigates the effect of COVID-19 on tourists’ intentions to choose a particular travel mode during the pandemic. Our findings show that the higher the perceived susceptibility of getting COVID-19 associated with the holiday journey, the lower the choices for collective travel modes. Furthermore, for those tourists who are more likely to take risks, their choices for collective travel modes are increased. The study recommends that public transport operators choose measures that increase the application of non-pharmaceutical interventions (NPIs) against pandemics while travelling; this may encourage the safe use of collective transport modes during a pandemic.