Background: Industry 4.0 technologies have been widely used in the railway industry, focusing mainly on maintenance and control tasks necessary in the railway infrastructure. Given the great potential that these technologies offer, the scientific community has come to use them in varied ways to solve a wide range of problems such as train failures, train station security, rail system control and communication in hard-to-reach areas, among others. For this reason, this paper aims to answer the following research questions: what are the main issues in the railway transport industry, what are the technologic strategies that are currently being used to solve these issues and what are the technologies from industry 4.0 that are used in the railway transport industry to solve the aforementioned issues? Methods: This study adopts a systematic literature review approach. We searched the Science Direct and Web of Science database inception from January 2017 to November 2021. Studies published in conferences or journals written in English or Spanish were included for initial process evaluation. The initial included papers were analyzed by authors and selected based on whether they helped answer the proposed research questions or not. Results: Of the recovered 515 articles, 109 were eligible, from which we could identify three main application domains in the railway industry: monitoring, decision and planification techniques, and communication and security. Regarding industry 4.0 technologies, we identified 9 different technologies applied in reviewed studies: Artificial Intelligence (AI), Internet of Things (IoT), Cloud Computing, Big Data, Cybersecurity, Modelling and Simulation, Smart Decision Support Systems (SDSS), Computer Vision and Virtual Reality (VR). This study is, to our knowledge, one of the first to show how industry 4.0 technologies are currently being used to tackle railway industry problems and current application trends in the scientific community, which is highly useful for the development of future studies and more advanced solutions. Funding: Colombian national organizations Minciencias and the Mining-Energy Planning Unit.

Public policies and economic incentives are widely used as a strategy to stimulate the use of green technologies and low-emission practices in the waterborne transport sector. Since the Paris Agreement, countries have been encouraged to implement more strategies to reduce greenhouse gas emissions and to build resilience against climate change impacts in developing countries. This article presents a literature review on policies, regulations, and programs that represent economic incentives to promote alternatives to decarbonize maritime and inland waterway transport in sixteen countries, including Colombia. More than one hundred thirty sources of information were reviewed, including official portals of governments, port authorities and organizations, and scientific articles; therefore, the incentives found were grouped into three categories: project financing, differentiated port tariffs, and incentives to cover onshore power service fees. As a result of this review, it was found that differentiated port tariffs were the most common type of incentive. Finally, the specific case of Colombia was analyzed, which provides a deeper perspective of current policies and measures aimed at encouraging the decarbonization of waterborne transport and compares them with the international panorama.

The focus of this article is inland waterway transport. Different problems in this domain have been studied due to the increase in waterway traffic globally. Industry 4.0 technologies have become an alternative for the possible solution of these problems. For this reason, this paper aims to answer the following research questions: (1) What are the main problems in transporting cargo by inland waterway? (2) What technological strategies are being studied to solve these problems? (3) What technologies from Industry 4.0 are used within the technological strategies to solve the exposed problems? This study adopts a Systematic Literature Review (SLR) approach. For this work, were recovered 645 articles, 88 of which were eligible, from which we could identify five domains corresponding to (1) traffic monitoring, (2) smart navigation, (3) emission reduction, (4) analytics with big data, and (5) cybersecurity. The strategies currently being considered combine navigation technologies, such as AIS (Automatic Identification System), which offers a large amount of data, with Industry 4.0 tools and mainly machine learning techniques, to take advantage of data collected over a long time. This study is, to our knowledge, one of the first to show how Industry 4.0 technologies are currently being used to tackle inland waterway transport problems and current application trends in the scientific community, which is a first step for the development of future studies and more advanced solutions.

This study reviews various green technological strategies integrated into vessels to mitigate environmental impact, focusing on atmospheric pollution and marine environment protection. The research is based on a systematic review of academic literature published between 2019 and 2024, using the Scopus and Web of Science databases and applying PRISMA criteria. The findings reveal that the main environmental issues in the naval sector include greenhouse gas emissions, harmful discharges, and invasive species that affect marine biodiversity. The analysis is framed within international regulations such as those established by the IMO and classification societies, where the most relevant indicators identified are the EEDI and EEXI. However, the results of this review emphasize that, while these regulations are fundamental, it is necessary to analyze further the technical and economic barriers affecting the widespread implementation of these technologies and develop incentive mechanisms that facilitate their adoption across different vessel types and sizes. Promising solutions include alternative fuels, new propulsion systems, and emission-reduction technologies. The conclusion underlines that although the sector is transitioning toward sustainability, economic and widespread implementation challenges remain.

The trend in the development of maritime and river propulsion systems is to make a transition from hydrocarbon to more environmentally friendly solutions. This contributes positively to the solution of the problems identified by the International Maritime Organization (IMO) regarding the high emissions of polluting gases emitted by maritime transportation. Currently, there is a wide variety of systems available due to the development of mobility technologies focused on decarbonization. This paper presents an analysis of technological alternatives for boats with electromobility applications and propulsion systems in the waterway field. First, a description of the operation of boats with electric motors, the different energy sources, and the alternative propulsion options is presented. Then, the electromobility technologies are characterized, analyzing the different configurations between the power source and the propulsion system. The results show a comparative table of technologies and their advantages and disadvantages. In addition, the most environmentally friendly technologies present significant challenges for large-scale implementation due to their recent development. In the short term, hybrid systems technologies present advantages over the others, as current systems are available, with the addition of equipment with higher efficiency and lower environmental impact.

The development of autonomous vessels and unmanned surface vehicles (USVs) has generated great interest in the scientific community due to their potential and advantages for use in various environments and applications. Several literature review papers have been produced from different perspectives, contributing to a better understanding of the topic and to the analysis of advances, challenges, and trends. We hypothesize that the greatest attention has been focused on the development of high-impact applications in the maritime sector. Additionally, we depart from the need to investigate the potential and advances of USVs in fluvial environments, which involve particular operating conditions, where there are different socio-environmental conditions and restrictions in terms of access to conventional energy sources and communication systems. In this sense, the main objective of this work is to study USVs in the particular context of small craft. The search for records was conducted in Scopus and Web of Science databases, covering studies published from 2000 to 16 May 2024. The methodology employed was based on the PRISMA 2020 guidelines, which is a widely recognized protocol that ensures quality and rigor in systematic reviews and bibliometric analyses. To optimize the data collection and selection process, the semaphore technique was additionally implemented, allowing for an efficient categorization of the studies found. This combined methodological approach facilitated a systematic and transparent evaluation of the literature. This study was developed based on three research questions about the evolution of research topics, areas of application, and types of algorithms related to USVs. The study of the evolution of works on USVs was carried out based on the results of the meta-analysis generated with the Bibliometrix tool. The study of applications and developments was carried out based on information obtained from the papers for six study categories: application environment, level of autonomy, application area, algorithm typology, methods, and electronic devices used. For each of the 387 papers identified in the databases, labeling was performed for the 359 screened papers with six study categories according to the availability of information in the title and In the categories application sector, autonomy level, application area and algorithm type/task, it was identified that most studies are oriented toward the maritime sector, the developments to achieve full autonomy for USVs, the development of designs or algorithms at the modeling and simulation level, and the development and implementation of algorithms for the GNC subsystems. Nevertheless, this research has revealed a much wider range of environments and applications beyond maritime, military, and commercial sectors. In addition, from the mapping of the types of algorithms used in the GNC architecture, the study provides information that can be used to guide the design of the subsystems that enable USV autonomy for civilian use in restricted environments.