Scientific Journal of Silesian University of Technology. Series Transport最新文献

{"title":"NEW STRATEGY THE FOR DESIGNATION OF THE INTEGRITY PARAMETER IN SBAS POSITIONING IN AIR TRANSPORT","authors":"M. Mrozik, J. Kozuba, K. Krasuski, J. Ćwiklak, Mieczysław Bakuła, Bilal Beldjilali","doi":"10.20858/sjsutst.2024.122.13","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.13","url":null,"abstract":"The article shows the results of a study on the determination of SBAS satellite positioning integrity parameters as a HPL and VPL protection levels. To this end, a modified algorithm was developed to determine the HPL and VPL protection levels from a common aircraft position navigation solution based on EGNOS and SDCM augmentation systems. The developed mathematical scheme was verified on real GNSS kinematic data recorded by two onboard Septentrio AsterRx2i and Trimble Alloy receivers installed on a Diamond DA 20-C aircraft. Based on the conducted tests, it was found that the HPL parameter does not exceed 12.24 m, while respectively the VPL does not exceed 18.01 m. In addition, in the course of the study it was found that the proposed EGNOS+SDCM solution improves the HPL/VPL integrity determination in relation to the EGNOS solution by 8÷66%. The mathematical scheme used in the study was also applied to designation the HPL/VPL terms for the UAV platform. The obtained results of the HPL/VPL values for the positioning of the aircraft and the UAV platform show a high efficiency of the developed algorithm for improving the integrity parameter.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"509 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140286871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PUBLIC-PRIVATE PARTNERSHIP PROCUREMENT TRANSPORT INFRASTRUCTURE DELIVERY: ASSESSING THE MANAGERIAL CAPABILITIES OF PUBLIC-SECTOR ORGANIZATIONS IN AFRICA","authors":"B. Olojede","doi":"10.20858/sjsutst.2024.122.14","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.14","url":null,"abstract":"The lingering imbalance between infrastructural services demand and supply poses serious threats to the fiscal budget balance from contingent liabilities of African countries. Despite the increasing private investment commitments and adoption of public-private partnership procurement (PPP) options to address the widening infrastructure gaps in Africa, the failure in the delivery of public infrastructure projects is yet a common phenomenon. This study therefore examined the managerial capabilities of public-sector organizations (PSOs), who steer the provisions of public infrastructure, to investigate their readiness to achieve the value for money from private funding and the benefits of PPP options. The study conducted a self-study structured questionnaire survey on professionals in PSOs in Africa, particularly Nigeria, who have been directly involved in the delivery of public infrastructure projects via PPP. The professionals were purposively sampled and the primary data obtained was subjected to descriptive and inferential analysis. The study revealed that the PSOs have internalized about 41 PPP-capabilities for the delivery of public infrastructure projects. Up to 40 PPP-capabilities were exhibited on an average score (41-60%) level, with mean score (MS) value range of 3.13 ≤ MS ≤ 3.70, for the public projects procured. The study established the existence of significant interdependence of p < 0.001, which indicated sufficient correlation between 31 PPP-capabilities and explained the 10 main components of managerial capabilities possessed by the PSOs. Some of the components clustered around public infrastructure planning and adaptability to PPP programme, project delivery parameters and control, suitable public infrastructure procurement knowledge, public policy awareness and innovation, and governance. The study provides information crucial for public infrastructure delivery success towards sustainable national economic recovery and development.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"137 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140403124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CALIBRATION OF MICROSCOPIC TRAFFIC SIMULATION OF URBAN ROAD NETWORK INCLUDING MINI-ROUNDABOUTS AND UNSIGNALIZED INTERSECTION USING OPEN-SOURCE SIMULATION TOOL","authors":"Mehmet Nedim Yavuz, Halit Özen","doi":"10.20858/sjsutst.2024.122.17","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.17","url":null,"abstract":"Microscopic traffic simulation models offer an effective way to analyze and assess different transportation systems thanks to their efficiency and reliability. As traffic management issues become more prevalent, notably in urban areas, simulation tools enable a significant opportunity to replicate real-world conditions before implementation. Therefore, the calibration of traffic simulation models plays a substantial role in obtaining accurate and confidential results. Nowadays, urban regions are facing the challenge of restricted space for developing traffic solutions. As a consequence of environmental restrictions, the use of mini-roundabouts rather than larger roundabouts is increasing. Based on the given literature review, it is seen that not much attention was given to the complex modeling and calibration of microsimulation models of mini-roundabouts and unsignalized intersections. The objective of this study is to offer the calibration of microscopic traffic simulation of urban road network, including closely located mini-roundabouts and unsignalized intersection. To this end, an open-source tool called SUMO (Simulation of Urban Mobility) was utilized as a simulation environment in this study. The necessary data for developing a microsimulation model in SUMO was gathered using a videography technique. The traffic count data and speed were considered performance measures between field observations and simulation outputs. The routeSampler tool of SUMO, which has recently emerged in the literature, was used to match traffic count data and the corresponding time interval for traffic volume data calibration. The calibration of car-following model parameters using a trial-and-error approach was employed based on mean absolute percent error (MAPE) between simulated speeds and field-measured speeds. According to the findings of the study, the simulation model fulfilled the calibration aims of the FHWA guideline and is suitable for further research.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"64 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140406455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WELDING OF 1.4462 DUPLEX STEEL USED IN MEANS OF ROAD TRANSPORT","authors":"B. Szczucka-Lasota, T. Wȩgrzyn","doi":"10.20858/sjsutst.2024.122.15","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.15","url":null,"abstract":"Materials with good mechanical and chemical properties (materials should be resistant to various types of corrosion) are proposed for the various structures of means of transport. For this reason, high-alloy steels, including duplex steels, are increasingly used in the automotive industry. The 1.4462 duplex steel used in means of road transport steel could be treated as an interesting high-strength stainless material used in the automotive industry. Generally, duplex steels have a high resistance to localized and uniform corrosion. The duplex and superduplex steels are assumed to be rather proper weldable materials; however, cracks could be observed both in the heat-affected zone (HAZ) and in the weld. The article analyses the influence of tubular cored metal arc (136) with active gas shield welding (process 136) parameters on the arrangement of correct joints used in tanker truck elements, as an example of welding in the automotive sector. Various mechanical tests checking the properties of joints were realized. The goal of the paper is to choose the correct welding parameters for elements of 1.4462 steel. The construction elements of a tanker truck are made by the 136 method of welding.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"18 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140408025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE EFFECTS OF ENVIRONMENTAL PECULIARITIES ON TRANSPORTATION INFRASTRUCTURE PERFORMANCE IN LAGOS METROPOLIS, NIGERIA: RESIDENTS' EXPERIENCES","authors":"A. Akanmu, U. Salisu","doi":"10.20858/sjsutst.2024.122.1","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.1","url":null,"abstract":"Efficient transportation infrastructure is pivotal for the seamless functioning of global cities, with coastal cities facing unique challenges due to environmental peculiarities. This study delves into how Lagos' environmental peculiarities impact transportation infrastructure performance, shedding light on both positive and negative implications. A comprehensive survey involving 1284 residents within Lagos Metropolis was conducted using multistage sampling techniques. A combination of descriptive (percentage and mean-weighted analysis) and inferential (Fisher’s exact test and Phi Cramer's V Test) statistics was adopted for data analysis. Major findings revealed that the environmental peculiarities in Lagos foster the use of multimodal infrastructure options and concurrently exert adverse effects on various facets of transportation infrastructure performance, including travel cost, commuting time, fare charges, wear and tear of infrastructure, and the overall cost of maintenance and repairs. The results of the Fisher’s exact test underscore the undeniable impact of Lagos' environmental peculiarities on transportation infrastructure performance (p = 0.000 < 0.05). This study concludes that high water tables, as a representative environmental peculiarity, substantially influence transportation infrastructure performance, shaping the mobility needs of residents. In light of these findings, the study advocates for the full implementation of sustainable infrastructure solutions. Recommendations include establishing robust drainage systems, incorporating corrosion-resistant materials, and adopting innovative technologies to mitigate the repercussions of rising sea levels on critical transportation infrastructure, enhancing its resilience in the face of environmental challenges.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"661 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140286596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NEED FOR SMART MOBILITY AND CHALLENGES AND OPPORTUNITIES FOR TRANSITIONING TOWARD IT IN CAR-DEPENDENT COUNTRIES: INSIGHTS FROM LITERATURE","authors":"Talal Almaghlouth, U. Gazder, Osama Abudayyeh","doi":"10.20858/sjsutst.2024.122.2","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.2","url":null,"abstract":"Car dependence is a trend brought about by the desire for comfortable transportation, in many countries around the world. After the invention and acceptance of automobiles, cities were designed with layouts that favored automobiles at the expense of other forms of transportation. However, the situation has changed with research and execution of plans for smart cities, with smart mobility transition taking centre stage. The purpose of this research is to highlight the need for transition to smart mobility, provide detailed description of various aspects of smart mobility and analyse the challenges and opportunities associated with the transition to smart mobility in car-dependent countries. A thorough and critical review of the literature has been done to achieve the aim of this study. Previous research efforts indicated that car-dependent cities have experienced several challenges in their transition to smart mobility, including inadequate infrastructure, low acceptance of new technological solutions, inadequate knowledge and framework for big data, financial constraints, data quality management, integration of data from different sources, privacy issues, and development of appropriate of government policies. There are several promising recommendations, which implementation is expected to help car-dependent countries overcome the above challenges and open opportunities for a successful transition. These recommendations include implementation of aggressive government policies, practicing greater inclusivity, and planning for the future of smart mobility by investing in Internet of Things (IoT) applications and reliable infrastructure. To facilitate the decision makers, challenges have been mapped with recommendations for transition to smart mobility, in light of the review findings.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"47 205","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140406003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EXAMINING THE SAFETY IMPACTS OF TRANSIT PRIORITY SIGNAL SYSTEMS USING SIMULATION TECHNIQUES","authors":"E. Doğan","doi":"10.20858/sjsutst.2024.122.4","DOIUrl":"https://doi.org/10.20858/sjsutst.2024.122.4","url":null,"abstract":"Transit Priority Signal (TPS) systems are increasingly used to improve traffic efficiency and reduce passenger waiting times. However, such systems may carry potential safety risks. This study aims to investigate the safety effects of TPS at intersections. Our study utilized the SUMO traffic simulation program to create a road network model containing nine signalized intersections. Subsequently, the TPS system was applied to selected bus routes within the road network, and the cases with and without TPS implementation were compared in terms of safety and performance. In safety-oriented comparisons, surrogate safety measures were employed, including number of conflict and Time to Collision (TTC). Signalized intersection performances were measured and compared in terms of the number and duration of stops. The analysis results indicate that TPS enhances safety and transportation performance for buses, but adversely impacts safety and transportation performance for passenger cars. This study underscores the importance of considering safety aspects in the implementation of TPS aimed at improving passenger transportation efficiency. These findings may contribute to the enhancement of public transportation infrastructure and the implementation of appropriate safety measures.","PeriodicalId":517903,"journal":{"name":"Scientific Journal of Silesian University of Technology. Series Transport","volume":"11 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140286370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}