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THOMAS, NICOLE A., DANE STUCKEL, CARL GUTWIN und LORIN J. ELIAS. „Directional collisions during a route-following task“. Journal of the International Neuropsychological Society 15, Nr. 2 (März 2009): 225–30. http://dx.doi.org/10.1017/s1355617709090328.
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AbstractNeurologically normal people tend to collide with objects on the right side more frequently than with objects located on the left side of space. This phenomenon could be attributable to pseudoneglect wherein individuals selectively attend to the left field. The current study investigated this effect using a virtual route-following task that was presented centrally, in the lower field, and in the upper field. Handedness was also examined. Fifty-two participants (four left handed) completed this task, and when presented in the lower field, more left-side collisions emerged. In the upper condition, this bias reversed direction to the expected rightward bias. In the central condition, there was no significant directional bias in collision behavior. An interaction between handedness and presentation condition indicated that left-handed participants experienced more right-side collisions in the central condition. Collectively, these results suggest that directional biases (i.e., left vs. right) in collision behavior are modulated by both location in the visual field (central, upper, or lower) and handedness. (JINS, 2009, 15, 225–230.)
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Tsou, Ming-Cheng, Sheng-Long Kao und Chien-Min Su. „Decision Support from Genetic Algorithms for Ship Collision Avoidance Route Planning and Alerts“. Journal of Navigation 63, Nr. 1 (01.12.2009): 167–82. http://dx.doi.org/10.1017/s037346330999021x.
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When an officer of the watch (OOW) faces complicated marine traffic, a suitable decision support tool could be employed in support of collision avoidance decisions, to reduce the burden and greatly improve the safety of marine traffic. Decisions on routes to avoid collisions could also consider economy as well as safety. Through simulating the biological evolution model, this research adopts the genetic algorithm used in artificial intelligence to find a theoretically safety-critical recommendation for the shortest route of collision avoidance from an economic viewpoint, combining the international regulations for preventing collisions at sea (COLREGS) and the safety domain of a ship. Based on this recommendation, an optimal safe avoidance turning angle, navigation restoration time and navigational restoration angle will also be provided. A Geographic Information System (GIS) will be used as the platform for display and operation. In order to achieve advance notice of alerts and due preparation for collision avoidance, a Vessel Traffic Services (VTS) operator and the OOW can use this system as a reference to assess collision avoidance at present location.
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Erginli, Mustafa, und Ibrahim Cil. „Deep-Learning-Based Floor Path Model for Route Tracking of Autonomous Vehicles“. Systems 10, Nr. 3 (15.06.2022): 83. http://dx.doi.org/10.3390/systems10030083.
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Real-time route tracking is an important research topic for autonomous vehicles used in industrial facilities. Traditional methods such as copper line tracking on the ground, wireless guidance systems, and laser systems are still used in route tracking. In this study, a deep-learning-based floor path model for route tracking of autonomous vehicles is proposed. A deep-learning floor path model and algorithm have been developed for highly accurate route tracking, which avoids collisions of vehicles and follows the shortest route to reach the destination. The floor path model consists of markers. Routes in the floor path model are created by using these markers. The floor path model is transmitted to autonomous vehicles as a vector by a central server. The server dispatches the target marker address to the vehicle to move. The vehicle calculates all possible routes to this address and chooses the shortest one. Marker images on the selected route are processed using image processing and classified with a pre-trained deep-CNN model. If the classified image and the image on the selected route are the same, the vehicle proceeds toward its destination. While the vehicle moves on the route, it sends the last classified marker to the server. Other autonomous vehicles use this marker to determine the location of this vehicle. Other vehicles on the route wait to avoid a collision. As a result of the experimental studies we have carried out, the route tracking of the vehicles has been successfully achieved.
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Namgung, Ho. „Local Route Planning for Collision Avoidance of Maritime Autonomous Surface Ships in Compliance with COLREGs Rules“. Sustainability 14, Nr. 1 (25.12.2021): 198. http://dx.doi.org/10.3390/su14010198.
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A maritime autonomous surface ship (MASS) ensures safety and effectiveness during navigation using its ability to prevent collisions with a nearby target ship (TS). This avoids the loss of human life and property. Therefore, collision avoidance of MASSs has been actively researched recently. However, previous studies did not consider all factors crucial to collision avoidance in compliance with the International Regulations for Preventing Collisions at Sea (COLREGs) Rules 5, 7, 8, and 13–17. In this study, a local route-planning algorithm that takes collision-avoidance actions in compliance with COLREGs Rules using a fuzzy inference system based on near-collision (FIS-NC), ship domain (SD), and velocity obstacle (VO) is proposed. FIS-NC is used to infer the collision risk index (CRI) and determine the time point for collision avoidance. Following this, I extended the VO using the SD to secure the minimum safe distance between the MASS and the TS when they pass each other. Unlike previous methods, the proposed algorithm can be used to perform safe and efficient navigation in terms of near-collision accidents, inferred CRI, and deviation from the course angle route by taking collision-avoidance actions in compliance with COLREGs Rules 5, 7, 8, and 13–17.
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Hughes, Merrick Stuart Macqueen, und Jacobus Adriaan Albertus Engelbrecht. „Autonomous navigation for multiple unmanned aerial vehicles (UAVs) in urban environments“. MATEC Web of Conferences 388 (2023): 04011. http://dx.doi.org/10.1051/matecconf/202338804011.
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This paper presents an autonomous navigation system for multiple unmanned aerial vehicles (UAVs) in urban environments. The navigation system comprises a long-term route planner and a short-term cooperative collision avoidance function. A 3D model of a real urban terrain is used to represent the environment within which the UAVs operate, and the system takes the motion constraints of the UAVs into account when performing planning. The navigation system enables multiple independent UAVs to travel from their departure points to their destinations while predicting and avoiding collisions with one another and with static terrain. Monte Carlo simulations on the system indicate a worst-case route planner replan rate of 11.65 %, route planner failure rate of 9.82×10-4 %, and collision resolution failure rate of 0.12 % for the collision avoidance function.
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Lu, Chao-Wei, Chao-Kuang Hsueh, Yung-Lin Chuang, Ching-Ming Lai und Fuh-Shyong Yang. „Marine Collision Avoidance Route Planning Model for MASS Based on Domain-Based Predicted Area of Danger“. Journal of Marine Science and Engineering 11, Nr. 9 (01.09.2023): 1724. http://dx.doi.org/10.3390/jmse11091724.
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When the own ship encounters target ships in a close-quarter situation, an officer on watch needs to safely and timely alter the course of the vessel to avoid a collision. If ECDIS can automatically collect the navigation parameters and plot areas of collision as quasi-static obstruction areas, it will be much easier for seafarers to implement effective route planning. Hence, this study focuses on developing the MCARP model as a theoretical concept based on the DPAD model and LCD model. By operating the MCARP using ArcGIS, DPADs and several effective collision avoidance routes can be generated and imported into ECDIS based on AIS information at large scales and ample time. The graphic overlay of DPADs and effective routes on ECDIS can serve as a collision avoidance strategy reference for the personnel controlling maritime autonomous surface ships. Finally, different ships encountering situations were input into a Transas navigational simulator. The simulation results showed that own ship could avoid collisions with multiple target ships at distances larger than the preset collision avoidance distances, which also indicated that MCARP is practically feasible.
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Miyake, Rina, und Hiroko Itoh. „Design and Safety Assessment of Recommended Route off the Western Coast of Izu O Shima Island“. Journal of Marine Science and Engineering 10, Nr. 8 (02.08.2022): 1060. http://dx.doi.org/10.3390/jmse10081060.
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Ship routeing systems (e.g., traffic separation schemes) have been established worldwide to ensure ship traffic safety. There are no specific measures to establish an effective ship route. We have previously proposed a method to design and assess the route comparison with the present traffic flow in the interest to establish an effective ship routeing system, particularly for recommended routes. The method consists mainly of the following procedures: understanding the existing phenomena and the issues in the target area by analyzing target traffic flow; designing safety measures; assessing the safety measures; and determining the optimal safety measure. This method was used to design and assess the recommended route off the western coast of Izu O Shima Island. This route has been in service since January 2018. The purpose of this study is to validate the proposed method. First, the technical details of the method are described. An automatic identification system (AIS) observation was conducted before and after the implementation to validate the effectiveness of the recommended route for reducing collisions. The results show that the recommended route effectively reduces the risk of collisions. More specifically, the proposed method was found to be useful when establishing an effective recommended route.
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Liu, Xin, Shuwei Ren, Lei Zhang, Wei Shen und Yubo Tu. „Research on Dynamic Path Planning and Tracking Control for Ship Collision Avoidance“. Journal of Physics: Conference Series 2607, Nr. 1 (01.10.2023): 012012. http://dx.doi.org/10.1088/1742-6596/2607/1/012012.
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Abstract Ship collisions are prevalent every year, leading to significant maritime traffic accidents. This paper presents research on dynamic path planning and tracking control for ship collision avoidance by integrating ship automatic avoidance technology to address this issue. We conducted a comprehensive study on artificial potential fields, trajectory tracking, and route trajectory tracking in response to the current state of ship collision avoidance and trajectory tracking. The study employed vector decomposition and slider control as research methods to analyze, optimize, and modify ship collision avoidance methods. Additionally, we carried out collision avoidance simulations using MATLAB to verify the stability and safety of ship trajectory tracking under various methods to advance the research on ship collision avoidance and trajectory. The proposed approach has the potential to significantly reduce ship collisions and enhance ship trajectory safety.
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Aldred, Rachel, Susana García-Herrero, Esther Anaya, Sixto Herrera und Miguel Ángel Mariscal. „Cyclist Injury Severity in Spain: A Bayesian Analysis of Police Road Injury Data Focusing on Involved Vehicles and Route Environment“. International Journal of Environmental Research and Public Health 17, Nr. 1 (21.12.2019): 96. http://dx.doi.org/10.3390/ijerph17010096.
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This study analyses factors associated with cyclist injury severity, focusing on vehicle type, route environment, and interactions between them. Data analysed was collected by Spanish police during 2016 and includes records relating to 12,318 drivers and cyclist involving in collisions with at least one injured cyclist, of whom 7230 were injured cyclists. Bayesian methods were used to model relationships between cyclist injury severity and circumstances related to the crash, with the outcome variable being whether a cyclist was killed or seriously injured (KSI) rather than slightly injured. Factors in the model included those relating to the injured cyclist, the route environment, and involved motorists. Injury severity among cyclists was likely to be higher where an Heavy Goods Vehicle (HGV) was involved, and certain route conditions (bicycle infrastructure, 30 kph zones, and urban zones) were associated with lower injury severity. Interactions exist between the two: collisions involving large vehicles in lower-risk environments are less likely to lead to KSIs than collisions involving large vehicles in higher-risk environments. Finally, motorists involved in a collision were more likely than the injured cyclists to have committed an error or infraction. The study supports the creation of infrastructure that separates cyclists from motor traffic. Also, action needs to be taken to address motorist behaviour, given the imbalance between responsibility and risk.
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Lee, Jeong-Seok, und Ik-Soon Cho. „Extracting the Maritime Traffic Route in Korea Based on Probabilistic Approach Using Automatic Identification System Big Data“. Applied Sciences 12, Nr. 2 (10.01.2022): 635. http://dx.doi.org/10.3390/app12020635.
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To protect the environment around the world, we are actively developing ecofriendly energy. Offshore wind farm generation installed in the sea is extremely large among various energies, and friction with ships occurs regularly. Other than the traffic designated area and the traffic separate scheme, traffic routes in other sea areas are not protected in Korea. Furthermore, due to increased cargo volume and ship size, there is a risk of collisions with marine facilities and marine pollution. In this study, maritime safety traffic routes that must be preserved are created to ensure the safety of maritime traffic and to prevent accidents with ecofriendly energy projects. To construct maritime traffic routes, the analysis area is divided, and ships are classified using big data. These data are used to estimate density, and 50% maritime traffic is chosen. This result is obtained by categorizing the main route, inner branch route, and outer branch route. The Korean maritime traffic route is constructed, and the width of the route is indicated. Furthermore, this route can be applied as a navigation route for maritime autonomous surface ships.
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Ohn, Sung-Wook, und Ho Namgung. „Requirements for Optimal Local Route Planning of Autonomous Ships“. Journal of Marine Science and Engineering 11, Nr. 1 (22.12.2022): 17. http://dx.doi.org/10.3390/jmse11010017.
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Ships transport large volumes of cargo, and are therefore major contributors to the global economy. Ship collisions can cause significant economic losses. Path-planning algorithms can prevent such collisions by suggesting the optimal path for navigation. Conventional path-planning algorithms are disadvantageous, because they do not consider the navigation practices followed by experienced navigators. Therefore, in this study, we developed the requirements for optimal local path planning of autonomous ships by considering the open sea, restricted waters, and two-ship and multi-ship interactions, in addition to the navigation practices adopted by navigators and rules in COLREGs part B. First, the navigation practices under various scenarios were collected. Subsequently, these practices were linked to COLREGs part B to extract the key rules and keywords related to collision avoidance. Finally, the requirements for generating the optimal local path were drafted based on the rules and keywords. The utility of the requirements was demonstrated by applying them to representative path-planning algorithms for the timely and accurate evaluation of their effectiveness. The proposed requirements can be utilized to improve the existing path-planning algorithms and develop superior algorithms in the future.
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Kohlbrenner, Sean M., Matthew K. Eager, Nilan T. Phommachanh, Christos Kastrisios, Val Schmidt und Amith Kashyap. „Toward a Marine Road Network for Ship Passage Planning and Monitoring“. Proceedings of the ICA 4 (03.12.2021): 1–4. http://dx.doi.org/10.5194/ica-proc-4-61-2021.
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Abstract. Safety of navigation is essential for the global economy as maritime trade accounts for more than 80% of international trade. Carrying goods by ship is economically and environmentally efficient, however, a maritime accident can cause harm to the environment and local economies. To ensure safe passage, mariners tend to use already familiar routes as a best practice; most groundings occur when a vessel travels in unfamiliar territories or suddenly changes its route, e.g., due to extreme weather. In highly trafficked areas, the highest risk for ships is that of collision with other vessels in the area. In these situations, a network of previously traversed routes could help mariners make informed decisions for finding safe alternative routes to the destination, whereas a system that can predict the routes of nearby vessels would ease the burden for the mariner and alleviate the risk of collision. The goal of this project is to utilize Automatic Identification System data to create a network of “roads” to promote a route planning and prediction system for ships that makes finding optimal routes easier and allows mariners on the bridge and Autonomous Surface Vehicles to predict movement of ships to avoid collisions. This paper presents the first steps taken toward this goal, including data processing through the usage of Python libraries, database design and development utilizing PostgreSQL, density map generation and visualizations through our own developed libraries, an A* pathfinding algorithm implementation, and an early implementation of an Amazon Web Services deployment.
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Koucheryavy, A., O. A. Mahmood und A. Paramonov. „Traffic Routing Method for the Internet of Things Based on the Minimum of Collisions Probability“. Proceedings of Telecommunication Universities 5, Nr. 3 (2019): 37–44. http://dx.doi.org/10.31854/1813-324x-2019-5-3-37-44.
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The article discusses the analysis of the main approaches to the route choices in the networks of the Internet of Things and suggests a method of choosing routes taking into account the probability of collisions, which allows to create a logical network structure. The proposed method is based on the seeking algorithm of the quickest route on the graph. This method was implemented by means of simulation modeling, with the help of which was estimated the effectiveness for networks with high density of units comparing with the methods, which are based on the evaluation of the length of the route.
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Bouffard, Mélanie, Yves Leblanc, Yves Bédard und Donald Martel. „Impacts de clôtures métalliques et de passages fauniques sur la sécurité routière et le déplacement des orignaux le long de la route 175 au Québec“. Projets entourant la route 175 136, Nr. 2 (11.05.2012): 8–15. http://dx.doi.org/10.7202/1009100ar.
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Les collisions de véhicules avec les orignaux, un phénomène qui représente une préoccupation majeure pour la sécurité routière, sont en augmentation depuis plusieurs années au Québec. Par exemple, plus de 50 collisions ont été répertoriées annuellement sur la route 175, un tronçon routier en réfection qui traverse la réserve faunique des Laurentides et qui est récemment passé de 2 à 4 voies. À échéance, 67 km de cette route auront été clôturés pour réduire les collisions impliquant l’orignal. Nos travaux visaient à documenter les impacts des clôtures métalliques hautes (2,4 m) et des structures connexes (passages fauniques, sorties d’urgence pour orignal, passages routiers anti-cervidés, etc.) qu’on y a installées sur la sécurité routière et le déplacement de l’orignal. Après 5 années de suivi, les occurrences d’orignaux à l’intérieur de l’emprise clôturée ont diminué de plus de 95 %, réduisant la fréquence annuelle des collisions avec des véhicules de 7,5 collisions (en 2006 et 2007) à aucune (en 2008 et 2009) dans la zone clôturée. En parallèle, la fréquentation des passages fauniques sous la route par les orignaux s’est accrue de 48 % entre 2009 et 2010 (de 189 à 279 passages documentés). Bien que les clôtures métalliques hautes se soient avérées très efficaces pour limiter les déplacements d’orignaux sur la chaussée et réduire les risques de collisions, la croissance des populations et la modification des patrons de déplacement de l’orignal semblent avoir engendré de nouvelles zones à risque le long de la route réaménagée.
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Tennyson, Jonathan, Laura K. McKemmish und Tom Rivlin. „Low-temperature chemistry using the R-matrix method“. Faraday Discussions 195 (2016): 31–48. http://dx.doi.org/10.1039/c6fd00110f.
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Techniques for producing cold and ultracold molecules are enabling the study of chemical reactions and scattering at the quantum scattering limit, with only a few partial waves contributing to the incident channel, leading to the observation and even full control of state-to-state collisions in this regime. A new R-matrix formalism is presented for tackling problems involving low- and ultra-low energy collisions. This general formalism is particularly appropriate for slow collisions occurring on potential energy surfaces with deep wells. The many resonance states make such systems hard to treat theoretically but offer the best prospects for novel physics: resonances are already being widely used to control diatomic systems and should provide the route to steering ultracold reactions. Our R-matrix-based formalism builds on the progress made in variational calculations of molecular spectra by using these methods to provide wavefunctions for the whole system at short internuclear distances, (a regime known as the inner region). These wavefunctions are used to construct collision energy-dependent R-matrices which can then be propagated to give cross sections at each collision energy. The method is formulated for ultracold collision systems with differing numbers of atoms.
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Nagayoshi, Masato, Simon J. H. Elderton, Kazutoshi Sakakibara und Hisashi Tamaki. „Reinforcement Learning Approach for Adaptive Negotiation-Rules Acquisition in AGV Transportation Systems“. Journal of Advanced Computational Intelligence and Intelligent Informatics 21, Nr. 5 (20.09.2017): 948–57. http://dx.doi.org/10.20965/jaciii.2017.p0948.
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In this paper, we introduce an autonomous decentralized method for directing multiple automated guided vehicles (AGVs) in response to uncertain delivery requests. The transportation route plans of AGVs are expected to minimize the transportation time while preventing collisions between the AGVs in the system. In this method, each AGV as an agent computes its transportation route by referring to the static path information. If potential collisions are detected, one of the two agents chosen by a negotiation-rule modifies its route plan. Here, we propose a reinforcement learning approach for improving the negotiation-rules. Then, we confirm the effectiveness of the proposed approach based on the results of computational experiments.
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Grosman, Paul D., Jochen A. G. Jaeger, Pascale M. Biron, Christian Dussault und Jean-Pierre Ouellet. „Évaluation de l’efficacité des mesures d’atténuation des accidents routiers impliquant l’orignal par la modélisation individu-centrée“. Projets entourant la route 175 136, Nr. 2 (11.05.2012): 16–21. http://dx.doi.org/10.7202/1009101ar.
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Les collisions routières impliquant l’orignal se produisent souvent à proximité des mares d’eau stagnante où se concentre le sel de déglaçage qui a une forte teneur en sodium, un élément qui attire les orignaux. Cette étude vise à évaluer l’efficacité du drainage de ces mares salines et de l’implantation de mares salines compensatoires comme mesure d’atténuation des collisions routières impliquant l’orignal. Une approche de modélisation individu-centrée a été utilisée pour prédire le comportement des orignaux en relation avec divers scénarios de gestion des mares salines le long de la route 175 au Québec. Le suivi télémétrique de 47 orignaux a permis de calibrer et valider le modèle. Les résultats suggèrent que l’élimination de toutes les mares salines se traduirait par une réduction de 79 % des traversées de la route par les orignaux. L’érection de clôtures munies de passages fauniques est une autre méthode reconnue pour réduire le risque de collisions, mais nous ne connaissons pas l’influence de l’espacement entre les passages fauniques sur la perméabilité de la route dans les secteurs clôturés. Nous proposons un cadre conceptuel pour modéliser l’impact de la distance entre les passages fauniques le long de la route 175 sur la perméabilité de la route aux déplacements des orignaux.
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Kim, Min-Jae, und Sang-Hwa Chung. „Efficient Route Management Method for Mobile Nodes in 6TiSCH Network“. Sensors 21, Nr. 9 (28.04.2021): 3074. http://dx.doi.org/10.3390/s21093074.
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The combination of time slotted access and channel hopping technology in IEEE 802.15 TSCH networks enables high reliability and low power operation to meet the stability and real-time requirements of industrial applications. Basically, TSCH and RPL, a routing protocol for TSCH, are proposed for static nodes that generate fewer control messages, so they allow collisions in shared cells when they exchange control messages. In a topology containing mobile nodes, the collision of control messages in a shared cell makes the network difficult to recover quickly. The proposed scheme minimizes the collision of control messages by allocating dedicated control cells to form preferred parent nodes quickly for mobile nodes. We also proposed a method for establishing a fixed route from the root node to the mobile node in RPL to minimize the delay time. Through the simulation using the 6TiSCH simulator, it was confirmed that the performance of the proposed method was approximately 2.5 times better in terms of overhead and resource use, and 33% better in terms of network participation time of mobile nodes compared with existing solutions.
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Li, W., K. Shigeta, K. Hasegawa, L. Li, K. Yano und S. Tanaka. „COLLISION VISUALIZATION OF A LASER-SCANNED POINT CLOUD OF STREETS AND A FESTIVAL FLOAT MODEL USED FOR THE REVIVAL OF A TRADITIONAL PROCESSION ROUTE“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W7 (12.09.2017): 255–61. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w7-255-2017.
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Recently, laser-scanning technology, especially mobile mapping systems (MMSs), has been applied to measure 3D urban scenes. Thus, it has become possible to simulate a traditional cultural event in a virtual space constructed using measured point clouds. In this paper, we take the festival float procession in the Gion Festival that has a long history in Kyoto City, Japan. The city government plans to revive the original procession route that is narrow and not used at present. For the revival, it is important to know whether a festival float collides with houses, billboards, electric wires or other objects along the original route. Therefore, in this paper, we propose a method for visualizing the collisions of point cloud objects. The advantageous features of our method are (1) a see-through visualization with a correct depth feel that is helpful to robustly determine the collision areas, (2) the ability to visualize areas of high collision risk as well as real collision areas, and (3) the ability to highlight target visualized areas by increasing the point densities there.
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Kim, Eui-Jin, Oh Hoon Kwon, Shin Hyoung Park, Dong-Kyu Kim und Koohong Chung. „Application of naïve Bayesian approach in detecting reproducible fatal collision locations on freeway“. PLOS ONE 16, Nr. 5 (18.05.2021): e0251866. http://dx.doi.org/10.1371/journal.pone.0251866.
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Detecting high-collision-concentration locations based solely on collision frequency may produce different results compared to those considering the severities of the collisions. In particular, it can lead government agencies focusing sites with a high collision frequency while neglecting those with a lower collision frequency but a higher percentage of injury and fatal collisions. This study developed systematic ways of detecting reproducible fatal collision locations (R) using the naïve Bayes approach and a continuous risk profile (CRP) that estimates the true collision risk by filtering out random noise in the data. The posterior probability of fatal collisions being reproducible at a location is estimated by the relationship between the spatial distribution of fatal-collision locations (i.e., likelihood) and the CRP (i.e., prior probability). The proposed method can be used to detect sites with the highest proxy measure of the posterior probability (PMP) of observing R. An empirical evaluation using 5-year traffic collision data from six routes in California shows that detecting R based on the PMP outperform those based on the SPF-based approaches or random selection, regardless of various conditions and parameters of the proposed method. This method only requires traffic collision and annual traffic volume data to estimate PMP that prioritize sites being R and the PMPs can be compared across multiple routes. Therefore, it helps government agencies prioritizing sites of multiple routes where the number of fatal collisions can be reduced, thus help them to save lives with limited resources of data collection.
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Aultman-Hall, Lisa, und Michael F. Adams. „Sidewalk Bicycling Safety Issues“. Transportation Research Record: Journal of the Transportation Research Board 1636, Nr. 1 (Januar 1998): 71–76. http://dx.doi.org/10.3141/1636-11.
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Bicycle route and safety data sets for 2,963 commuter cyclists in Ottawa and Toronto, Canada, containing cyclist characteristics, collision and fall history, and regular commute route, are used for this analysis. Previous analyses found sidewalk collisions and fall and injury rates significantly higher on sidewalks than on roads or paths. Of the 52 events reported on sidewalks, none were reported to police and would, therefore, not be found in a police accident database. These events did result in injuries, and in two cases major injuries. This analysis has found that commuter cyclists in Ottawa use sidewalks primarily on major roads (not necessarily high-speed roads) and often to cross bridges or to take shortcuts where no road exists. Toronto commuter cyclists use sidewalks primarily on high-volume multilane roads. Some Toronto cyclists still use sidewalks when bicycle lanes are provided. A slightly higher proportion of women are sidewalk cyclists in Ottawa; however, no age relationship was found. Sidewalk cyclists reported proportionally more near misses with bicycles in the previous month. A relatively large number of sidewalk collisions are with other bicycles. The most significant result of the analysis is that sidewalk cyclists have higher event rates on roads than nonsidewalk cyclists.
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Qu, Xiao, und Wei Gang Zheng. „Design of Ship Anti-Collision Alarm System Based on Laser Range-Finding“. Applied Mechanics and Materials 496-500 (Januar 2014): 1502–5. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.1502.
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This paper introduces the design of a laser rangefinder ship collision avoidance warning system , laser distance sensor and two degrees of freedom PTZ constituted the system. the horizontal and vertical direction to achieve dynamic scanning . Real-time monitoring of the target vessel and the surrounding vessels ( obstructions ) distance , When entering the test vessel and the surrounding areas of the ship reaches the set distance of the minimum distance , alarm system achieve sound and light alarm for ship driver promptly adjusting the route for more time. Therefore reducing ship collisions happened.
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Vukša, Srđan, Pero Vidan, Mihaela Bukljaš und Stjepan Pavić. „Research on Ship Collision Probability Model Based on Monte Carlo Simulation and Bi-LSTM“. Journal of Marine Science and Engineering 10, Nr. 8 (15.08.2022): 1124. http://dx.doi.org/10.3390/jmse10081124.
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The efficiency and safety of maritime traffic in a given area can be measured by analyzing traffic density and ship collision probability. Maritime traffic density is the number of ships passing through a given area in a given period of time. It can be measured using vessel tracking systems, such as the Automatic Identification System (AIS). The information provided by AIS is real-time data designed to improve maritime safety. However, the AIS data can also be used for scientific research purposes to improve maritime safety by developing predictive models for collisions in a research area. This article proposes a ship collision probability estimation model based on Monte Carlo simulation (MC) and bidirectional long short-term memory neural network (Bi-LSTM) for the maritime region of Split. The proposed model includes the processing of AIS data, the verification of AIS data, the determination of ports and ship routes, MC and the collision probability, the Bi-LSTM learning process based on MC, the ship collision probability for new or existing routes, and the traffic density. The results of MC, i.e., traffic/vessel route and density, and collision probability for the study area can be used for Bi-LSTM training with the aim of estimating ship collision probability. This article presents the first part of research that includes MC in detail, followed by a preliminary result based on one day of processed AIS data used to simulate MC and propose a model architecture that implements Bi-LSTM for ship collision probability estimation.
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Pattard, Thomas, und Jan M. Rost. „A route to chaos in classical atom–diatom collisions“. Chemical Physics Letters 291, Nr. 3-4 (Juli 1998): 360–66. http://dx.doi.org/10.1016/s0009-2614(98)00602-2.
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Saveliev, Anton, Dmitry Anikin, Vadim Agafonov und Gennady Erokhin. „Modeling the trajectories of a group of unmanned aerial vehicles based on the ADRRT-Connect algorithm in the problem of placing seismic sensors“. Robotics and Technical Cybernetics 12, Nr. 3 (30.09.2024): 184–93. http://dx.doi.org/10.31776/rtcj.12303.
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Optimal route planning is a key aspect of successfully delivering geosensors using unmanned aerial vehicles (UAVs) to geographically distributed targets. The optimality of the route depends on the time required to plan the route and execute the flight to a target or group of targets, considering traffic safety and dynamic constraints. The trajectory calculation algorithm must always find a route, if one exists, and if it is impossible to find one, inform the operator about this circumstance. This article proposes a method based on a set of algorithms that ensure efficient distribution of targets among group members based on information about the targets and characteristics of the unmanned aerial vehicles used. The method involves constructing optimal routes considering minimizing path length, avoiding sharp turns and loops, as well as avoiding obstacles and avoiding collisions with other unmanned aerial vehicles within the group. To test the proposed method, software was developed using the ROS/Gazebo en-vironment. The proposed method is a comprehensive solution to the problem of optimal route planning for UAVs with an emphasis on efficiency, safety, and efficiency in the context of geosensor delivery using unmanned aerial vehicles.
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SCHLENOFF, CRAIG, STEPHEN BALAKIRSKY, MIKE USCHOLD, RON PROVINE und SCOTT SMITH. „Using ontologies to aid navigation planning in autonomous vehicles“. Knowledge Engineering Review 18, Nr. 3 (September 2003): 243–55. http://dx.doi.org/10.1017/s0269888904000050.
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This paper explores the hypothesis that ontologies can be used to improve the capabilities and performance of on-board route planning for autonomous vehicles. We name a variety of general benefits that ontologies may provide, and list numerous specific ways that ontologies may be used in different components of our chosen infrastructure: the 4D/RCS system architecture developed at NIST. Our initial focus is on simple roadway driving scenarios where the controlled vehicle encounters objects in its path. Our approach is to develop an ontology of objects in the environment, in conjunction with rules for estimating the damage that would be incurred by collisions with the different objects in different situations. Automated reasoning is used to estimate collision damage; this information is fed to the route planner to help it decide whether to avoid the object. We describe our current experiments and plans for future work.
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Cai, Wenchao, und Yadong Zhou. „Preventing aircraft from wildlife strikes using trajectory planning based on the enhanced artificial potential field approach“. Metascience in Aerospace 1, Nr. 2 (2024): 219–45. http://dx.doi.org/10.3934/mina.2024010.
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<abstract> <p>Wildlife strikes refer to collisions between animals and aircraft during flight or taxiing. While such collisions can occur at any phase of a flight, the majority occur during takeoff and landing, particularly at lower altitudes. Given that most reported collisions involve birds, our focus was primarily on bird strikes, in line with statistical data. In the aviation industry, aircraft safety takes precedence, and attention must also be paid to optimizing route distances to minimize operational costs, posing a multi-objective optimization challenge. However, wildlife strikes can occur suddenly, even when aircraft strictly adhere to their trajectories. The aircraft may then need to deviate from their planned paths to avoid these collisions, necessitating the adoption of alternative routes. In this article, we proposed a method that combines artificial potential energy (APE) and morphological smoothing to not only reduce the risk of collisions but also maintain the aircraft's trajectory as closely as possible. The concept of APE was applied to flight trajectory planning (TP), where the aircraft's surroundings were conceptualized as an abstract artificial gravitational field. This field exerts a "gravitational force" towards the destination, while bird obstacles exert a "repulsive force" on the aircraft. Through simulation studies, our proposed method helps smooth the trajectory and enhance its security.</p> </abstract>
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Wibowo, Edy, Naily Ulya, Putut Marwoto, Suwandi und Suproyogi. „The dynamics of Lato Lato ball collisions“. Physics Education 59, Nr. 5 (02.07.2024): 055002. http://dx.doi.org/10.1088/1361-6552/ad5780.
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Abstract Lato Lato is a toy that consists of two identical solid balls that are secured together with a rope and can be used as a learning tool in physics. In this study, we examined why the Lato Lato toy uses two balls with the same mass rather than balls with different masses. The collision of the two Lato Lato balls can be considered an elastic collision. The two balls move symmetrically at the same velocity and form a semi-circular route with opposing motion directions when we use Lato Lato with the same ball mass ( m 2 = m 1 ). The angular momentum of the two balls is also the same but in opposite directions, so they cancel each other out. Hence, the two balls travel steadily when Lato Lato is performed. This condition leads to a balanced movement of the Lato Lato system and prevents it from collapsing. On the other hand, because of their disparate masses ( m 2 > m 1 ), the two balls of Lato Lato move in an imbalanced manner. A lighter ball travels farther because it moves more quickly than a heavier ball. The angular momentum of the two balls is in opposite directions but not of the same magnitude, so they do not cancel each other out. This results in unstable movement of the two balls when Lato Lato is played. Therefore, the two balls no longer collide centrally, like in Lato Lato, with the same mass, but the collision is glancing. Then, the motion of the two balls facilitates collapse easily. This work can enrich students’ understanding of collisions beyond the collisions of two objects commonly discussed in textbooks.
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Bachi, Nicolás, Sebastian Otranto und Karoly Tőkési. „Electron-Impact Ionization of Carbon“. Atoms 11, Nr. 2 (20.01.2023): 16. http://dx.doi.org/10.3390/atoms11020016.
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We present ionization cross-sections of collisions between electrons and carbon atoms using the classical trajectory Monte Carlo method. Total cross-sections are benchmarked against the reported experimental data and the predictions of numerically intensive theoretical methods as well as pioneering calculations for this collision system. At impact energies greater than about 100 eV, the present results are in very good agreement with the generalized oscillator strength formulation of the Born approximation as well as with the experimental data. Limitations inherent to a purely classical description of the electron impact ionization process at low impact energies are detected and analyzed, suggesting a clear route for future studies.
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Ahmed, Gamil, und Tarek Sheltami. „Novel Energy-Aware 3D UAV Path Planning and Collision Avoidance Using Receding Horizon and Optimization-Based Control“. Drones 8, Nr. 11 (19.11.2024): 682. http://dx.doi.org/10.3390/drones8110682.
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Unmanned Aerial Vehicles (UAVs) have gained significant popularity in recent years thanks to their agility, mobility, and cost-effectiveness. However, UAV navigation presents several challenges, particularly in path planning, which requires determining an optimal route while avoiding obstacles and adhering to various constraints. Another critical challenge is the limited flight time imposed by the onboard battery. This paper introduces a novel approach for energy-efficient three-dimensional online path planning for UAV formations operating in complex environments. We formulate the path planning problem as a minimization optimization problem, and employ Mixed-Integer Linear Programming (MILP) to achieve optimal solutions. The cost function is designed to minimize energy consumption while considering the inter-collision and intra-collision avoidance constraints within a limited detection range. To achieve this, an optimization approach incorporating Receding Horizon Control (RHC) is applied. The entire path is divided into segments or sub-paths, with constraints used to avoid collisions with obstacles and other members of the fleet. The proposed optimization approach enables fast navigation through dense environments and ensures a collision-free path for all UAVs. A path-smoothing strategy is proposed to further reduce energy consumption caused by sharp turns. The results demonstrate the effectiveness and accuracy of the proposed approach in dense environments with high risk of collision. We compared our proposed approach against recent works, and the results illustrate that the proposed approach outperforms others in terms of UAV formation, number of collisions, and partial path generation time.
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Vagushchenko, L. L., und A. J. Kozachenko. „DETERMINATION OF MANEUVER TO RETURN TO THE PASSAGE ROUTE“. Shipping & Navigation 34, Nr. 1 (05.05.2023): 10–20. http://dx.doi.org/10.31653/2306-5761.34.2023.10-20.
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This study presents an algorithmic approach to finding an effective -maneuver for multi-ship situations, where a ship deviates from its transition route to avoid collision with other vessels. The proposed algorithm involves the enumeration of a representative discrete set of solutions to find a - maneuver that ensures a safe return to the transition route. The maneuver starts at the minimum distance from the own ship and has the required lateral distance and angle of approach to the route. The algorithm also addresses situations with several targets by introducing virtual targets and automatically finding a maneuver that avoids collision. To aid decision-making, the study develops a two-dimensional matrix that provides the coordinates of the angle of approach to the route and the distance from the own ship to the start of the maneuver, where the cross-track distance is equal to a given value. The matrix presents the sufficient, acceptable, and unacceptable -maneuver variants based on the shortest distance from the own ship to the targets. The matrix is represented by a color-coded diagram that allows for easy selection of a suitable maneuver providing the necessary offset from the track line. The study accounts for the dynamics of the own ship in a simplified way by assuming that course changes are made within a given radius. To validate the proposed algorithms, a program was implemented in Delphi programming language, and tests were carried out in various multi-ship situations. The results confirmed the effectiveness of the proposed algorithms in selecting - maneuvers for returning to the transition route while avoiding collisions. In summary, the study presents a novel algorithmic approach for selecting an effective - maneuver in multi-ship situations, accounting for the dynamics of the own ship and using a colorcoded diagram for easy selection. The proposed algorithms have been validated through simulations, highlighting their potential for improving the safety and efficiency of maritime navigation. Keywords: collision avoidance, -manoeuver, enumerative method, diagram to select manoeuver.
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Kawabe, Tomoya, Tatsushi Nishi und Ziang Liu. „Flexible Route Planning for Multiple Mobile Robots by Combining Q–Learning and Graph Search Algorithm“. Applied Sciences 13, Nr. 3 (31.01.2023): 1879. http://dx.doi.org/10.3390/app13031879.
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The use of multiple mobile robots has grown significantly over the past few years in logistics, manufacturing and public services. Conflict–free route planning is one of the major research challenges for such mobile robots. Optimization methods such as graph search algorithms are used extensively to solve route planning problems. Those methods can assure the quality of solutions, however, they are not flexible to deal with unexpected situations. In this article, we propose a flexible route planning method that combines the reinforcement learning algorithm and a graph search algorithm for conflict–free route planning problems for multiple robots. In the proposed method, Q–learning, a reinforcement algorithm, is applied to avoid collisions using off–line learning with a limited state space to reduce the total learning time. Each vehicle independently finds the shortest route using the A* algorithm, and Q–learning is used to avoid collisions. The effectiveness of the proposed method is examined by comparing it with conventional methods in terms of computation time and the quality of solutions. Computational results show that for dynamic transportation problems, the proposed method can generate the solutions with approximately 10% of the computation time compared to the conventional Q–learning approach. We found that the required computation time is linearly increased with respect to the number of vehicles and nodes in the problems.
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Liu, Guiyun, Cong Shu, Zhongwei Liang, Baihao Peng und Lefeng Cheng. „A Modified Sparrow Search Algorithm with Application in 3d Route Planning for UAV“. Sensors 21, Nr. 4 (09.02.2021): 1224. http://dx.doi.org/10.3390/s21041224.
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The unmanned aerial vehicle (UAV) route planning problem mainly centralizes on the process of calculating the best route between the departure point and target point as well as avoiding obstructions on route to avoid collisions within a given flight area. A highly efficient route planning approach is required for this complex high dimensional optimization problem. However, many algorithms are infeasible or have low efficiency, particularly in the complex three-dimensional (3d) flight environment. In this paper, a modified sparrow search algorithm named CASSA has been presented to deal with this problem. Firstly, the 3d task space model and the UAV route planning cost functions are established, and the problem of route planning is transformed into a multi-dimensional function optimization problem. Secondly, the chaotic strategy is introduced to enhance the diversity of the population of the algorithm, and an adaptive inertia weight is used to balance the convergence rate and exploration capabilities of the algorithm. Finally, the Cauchy–Gaussian mutation strategy is adopted to enhance the capability of the algorithm to get rid of stagnation. The results of simulation demonstrate that the routes generated by CASSA are preferable to the sparrow search algorithm (SSA), particle swarm optimization (PSO), artificial bee colony (ABC), and whale optimization algorithm (WOA) under the identical environment, which means that CASSA is more efficient for solving UAV route planning problem when taking all kinds of constraints into consideration.
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Batista, Josias G., Geraldo L. B. Ramalho, Marcelo A. Torres, Anderson L. Oliveira und Daniel S. Ferreira. „Collision Avoidance for a Selective Compliance Assembly Robot Arm Manipulator Using Topological Path Planning“. Applied Sciences 13, Nr. 21 (24.10.2023): 11642. http://dx.doi.org/10.3390/app132111642.
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Industrial applications with robotic manipulators have grown and made production systems increasingly efficient. However, there are still some limitations that can delay production, causing losses. Several factors, such as accidents and collisions of manipulator robots with operators and other machines, can cause unforeseen stops. Thus, this work aims to develop a trajectory planning method to avoid collisions applied to a selective compliance assembly robot arm (SCARA) robotic manipulator in the context of collaborative robotics. The main contribution of this paper is a path planning method based on mathematical morphology, named topological path planning (TPP). Through some evaluation metrics such as the number of path points, computing time, distance, standard deviation of the joint acceleration, and maximum acceleration rate along the path, we show that TPP is a collision-free, deterministic, and predictable route planning. In our experiments, our proposal presented better results for applications in industrial robotic manipulators when compared to the probabilistic roadmap method (PRM) and TPP*, a particular case of TPP that is similar to the generalized Voronoi diagram (GVD).
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Ohkawa, Shuto, Kiyoshi Ueda, Takumi Miyoshi, Taku Yamazaki, Ryo Yamamoto und Nobuo Funabiki. „Relay Node Selection Methods for UAV Navigation Route Constructions in Wireless Multi-Hop Network Using Smart Meter Devices“. Information 16, Nr. 1 (05.01.2025): 22. https://doi.org/10.3390/info16010022.
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Unmanned aerial vehicles (UAVs) offer solutions to issues like traffic congestion and labor shortages. We developed a distributed UAV management system inspired by virtual circuit and datagram methods in packet-switching networks. By installing houses with wireless terminals, UAVs navigate routes in a multi-hop network, communicating with ground nodes. UAVs are treated as network packets, ground devices are treated as routers, and their connections are treated as links. Activating all nodes as relays increases control message traffic and node load. To optimize connectivity, we minimize relay nodes, connecting non-relay nodes to the nearest relay. This study proposes four relay node selection methods: random selection, two adjacency-based methods, and our innovative approach using Multipoint Relay (MPR) from the Optimized Link State Routing Protocol (OLSR). We evaluated these methods according to their route construction success rates, relay node counts, route lengths, and so on. The MPR-based method proved most effective for UAV route construction. However, fewer relay nodes increase link collisions, and we identify the minimum relay density needed to balance efficiency and conflict reduction.
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Perumal, Thiyagarajan. „STATISTICAL MARKOV MODEL BASED NATURAL INSPIRED GLOWWORM SWARM MULTI-OBJECTIVE OPTIMIZATION FOR ENERGY EFFICIENT DATA DELIVERY IN MANET“. Information Technology And Control 49, Nr. 2 (16.06.2020): 333–47. http://dx.doi.org/10.5755/j01.itc.49.2.23554.
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An interference and collision is a significant problem to be solved in Mobile Ad Hoc Network (MANET). Few techniques were developed in existing work to perform energy aware routing in MANET. But, handling both interference and collision on route path was remained open issues which increases the energy usage and reduces the throughput of MANET. In order to overcome such limitations, Statistical Markov Model Based Natural Inspired Glowworm Multi-objective Optimization (SMM-NIGMO) technique is proposed. The SMM-NIGMO technique contains three key processes namely interference prediction, optimal node selection, route path identification. The SMM-NIGMO technique at first proposes a Statistical Markov Model to determine the interference level of each mobile node in MANET at the time ‘ ’. After that, SMM-NIGMO Technique designs a Natural Inspired Glowworm Swarm Multi-Objective Optimization (NIGSMO) algorithm to carry out the optimal node selection process in MANET. During this process, SMM-NIGMO Technique finds the mobile nodes with lower inferences and higher residual energy as optimal in dynamic environment. After discovering the best nodes, SMM-NIGMO Technique uses the Request-To-Send (RTS) and Clear-To-Send (CTS) mechanism for identifying the best route path in MANET. During the route path finding process, SMM-NIGMO Technique selects the mobile node to transmit the packets to destination without any collisions. As a result, SMM-NIGMO Technique enhances the performance of energy efficient data delivery in MANET as compared to existing works. The simulation of SMM-NIGMO Technique is performed using parameters such as throughput, energy consumption, packet loss rate and end to end delay. The simulation result depicts that the SMM-NIGMO Technique is able to improve the throughput and also reduces the energy consumption of data transmission in MANET as compared to state-of-the-art works.
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Hou, Rong, und Pengfei Zhang. „A-star Ant Colony Fusion Optimisation for Unmanned Ground Vehicle Route Planning“. Journal of Physics: Conference Series 2891, Nr. 11 (01.12.2024): 112001. https://doi.org/10.1088/1742-6596/2891/11/112001.
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Abstract Route planning technology of Unmanned Ground Vehicle (UGV) is a key issue in robotics, with the goal of avoiding obstacles and moving quickly to the target point. Aiming at the problem of easy collision with obstacles when utilizing the conventional A-star algorithm for global route planning, an improved turning mechanism is proposed to avoid collision. Aiming at the problems of longer routes and insufficiently smooth routes introduced by it, an improved A-star ant colony fusion algorithm for UGV route planning is proposed by combining the local planning capability of the ant colony algorithm. The A-star algorithm with an improved turning mechanism is fused with an ant colony algorithm to iteratively optimize the route length and route smoothness progressively. Simulation results show that the improved A-star ant colony fusion algorithm is able to avoid obstacles, reduce the length of the planned route by at least 2.34%, and improve the route smoothness by at least 5.62% compared to the A-star algorithm. It is beneficial for UGV to accomplish the corresponding tasks quickly on the basis of ensuring its obstacle avoidance.
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Hanashi, Abdalla M., und Saleh Algoul. „The Effectiveness of Dynamic Probabilistic Flooding in On-Demand Routing Protocols for MANETs was Assessed Through a Performance Analysis“. European Journal of Theoretical and Applied Sciences 1, Nr. 5 (01.09.2023): 935–41. http://dx.doi.org/10.59324/ejtas.2023.1(5).80.
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In mobile ad hoc networks (MANET), broadcasting is widely used in route discovery and many other network services. The efficiency of broadcasting protocol can affect the performance of the entire network. As such, the simple flooding algorithm aggravates a high number of unnecessary packet rebroadcasts, causing contention and packet collisions. Proper use of probabilistic method can reduce the number of rebroadcasting, therefore reduce the chance of contention and collision among neighboring nodes. A good probabilistic broadcast protocol can achieve high save rebroadcast and low collision. In this paper, we propose a dynamic probabilistic approach when nodes move according to way point mobility and compare it with simple flooding AODV and fixed probabilistic scheme. Our approach dynamically set the rebroadcasting probability according to the number of nieghbors nodes distributed in the ad hoc network. Simulation results show our approach performs better than both simple flooding and fixed probabilistic flooding.
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Boshier, Roger. „"Have you got it?" Overcoming the futility of training mariners about collision regulations“. Canadian Journal for the Study of Adult Education 22, Nr. 2 (04.04.2010): 47–63. http://dx.doi.org/10.56105/cjsae.v22i2.971.
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Despite aids to navigation, there are too many collisions involving deep-sea ships, tugs, workboats, fishing vessels, and recreational boats. Nautical trainers claim to teach collision regulations (COLREGS), but training has little to do with learning. Most mariners have only a surface (or no) understanding of maritime "rules of the road." In British Columbia, collisions have caused multiple fatalities and traumatized rescuers. Lecturing is not a good way to prevent collisions at sea. The British Columbia Institute of Technology's Marine Campus is committed to "excellence in training." The author reflects on his experience as a student there and suggests the institution adopt less authoritarian and more participatory, engaging, and respectful ways of fostering learning. Teaching COLREGS is as much a theoretical as a practical problem. Marine institutes should back away from training, put less focus on teaching and more on having people learn together. Résumé Malgré les aides à la navigation, il y a trop de collisions impliquant les navires de haute mer, remorqueurs, bateaux de travail, de pêche et les bateaux de plaisance. Les formateurs nautiques prétendent quʼils enseignent les règlements pour prévenir les abordages (COLREGS), mais la formation a peu à voir avec lʼapprentissage. La plupart des gens de mer n’ont quʼune compréhension en surface (ou même aucune compréhension) des “règles de la route” maritimes. En Colombie-Britannique, les collisions ont causé plusieurs morts ainsi que de nombreux sauveteurs traumatisés. Le cours magistral nʼ’est pas la bonne façon de prévenir les collisions en mer. Le campus marin de l’Institut de Technology de la Colombie-Britannique sʼest engagé à offrir une formation dʼexcellence. Lʼauteur reflète sur son expérience en tant quʼ’étudiant auprès de lʼInstitut et suggère à lʼInstitut dʼadopter des méthodes moins autoritaires, plus participatives, engageantes et respectueuses afin de favoriser un meilleur apprentissage. Lʼenseignement des règlements pour prévenir les abordages est un problème théorique autant que pratique. Les instituts maritimes devraient prendre du recul face à la formation, placer moins dʼ’importance sur lʼenseignement et mettre plutôt lʼemphase sur le fait que les gens doivent apprendre ensemble.
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Agapov, Mikhail. „Three Berths at the Village of Novy Port“. Sibirica 23, Nr. 1 (01.03.2024): 66–98. http://dx.doi.org/10.3167/sib.2024.230103.
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Abstract This article examines the local history of the Northern Sea Route using the Yamal settlement of Novy Port as a case study. Shifting the focus of research from the capital-based decision-making centers to the anchor points of the Transpolar Route makes it possible to see complex collisions, alternative options, deviations from plans, and other failures, without which it is impossible to implement such large-scale projects as the Northern Sea Route. Novy Port was assigned the role of one of the outposts of the Soviet colonization of the Arctic. At each of the identified stages of the history of Novy Port, its modus vivendi was formulated anew, which reflected a change in paradigms in the development of the Northern Sea Route.
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Gong, Haonan. „Application of Viscoelastic Materials in Ship Collision“. Journal of Contemporary Educational Research 5, Nr. 11 (30.11.2021): 118–24. http://dx.doi.org/10.26689/jcer.v5i11.2690.
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With the expansion of global trade routes, ship collision has become a major problem. This article proposes an approach by laying viscoelastic material on the inner side of the ship to increase the crashworthiness. By using the nonlinear finite element model software, this study simulates ship collisions as well as models and analyzes ships along with viscoelastic materials. The results from the simulation suggest that viscoelastic materials can effectively protect ships during collisions.
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Villard, Marc-André, Marc J. Mazerolle und Samuel Haché. „L’impact des routes, au-delà des collisions : le cas des oiseaux forestiers et des amphibiens“. Le Naturaliste canadien 136, Nr. 2 (11.05.2012): 61–65. http://dx.doi.org/10.7202/1009108ar.
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Bien que plus difficiles à quantifier, les effets indirects des routes sur la faune devraient être considérés au même titre que la mortalité routière, car certaines espèces évitent les abords des routes au moins durant une partie de l’année, ce qui peut mener à une fragmentation plus ou moins permanente de leurs populations. D’autre part, on observe chez plusieurs espèces un effet de bordure suivant lequel les abords des routes constituent un habitat de qualité marginale en raison du bruit, des substances et particules projetées par le passage des véhicules, des substances utilisées pour l’entretien routier (p. ex. sels de déglaçage) ou d’autres facteurs. Les oiseaux forestiers étudiés s’avèrent sensibles à la présence de routes à circulation intense, probablement en raison de la pollution sonore, alors qu’une espèce étudiée s’est avérée relativement tolérante à la construction d’une route de gravier. Quant aux amphibiens, les juvéniles en dispersion de 3 des 5 espèces étudiées semblaient éviter la traversée de routes pavées. Les gestionnaires de l’environnement devraient planifier l’aménagement des réseaux routiers dans la perspective du paysage afin d’éviter de dégrader ou de fragmenter les habitats critiques et de créer des barrières pour les mouvements saisonniers des espèces sensibles.
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Liu, Zihao, Dan Zhou, Zhongyi Zheng, Zhaolin Wu und Longhui Gang. „An Analytic Model for Identifying Real-Time Anchorage Collision Risk Based on AIS Data“. Journal of Marine Science and Engineering 11, Nr. 8 (05.08.2023): 1553. http://dx.doi.org/10.3390/jmse11081553.
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With the increasing volume of ship traffic, maritime traffic safety is facing a great challenge because the traffic in port becomes more and more crowded and complicated, which will make ship collisions more likely to happen. As a special water area of the port, the anchorage is also threatened by collision risk all the time. For accurately assessing the collision risk in anchorage and its adjacent waters in real time, this paper proposed an analytic model based on Automatic Identification System (AIS) data. The proposed anchorage collision risk model was established in microscopic, macroscopic, and complexity aspects, which considered ship relative motion, anchorage characteristics, and ship traffic complexity, respectively. For validation, the AIS data of the anchorages near the Shandong Peninsular were used to carry out a series of experiments. The results show that the proposed model can identify the anchorage collision risk effectively and has an advantage in dealing with complicated scenarios. The proposed anchorage collision risk model can help maritime surveillance better monitor and organize the ship traffic near the port and provide mariners with a reference about the collision risk situation of the anchorage on their route, which are important to improving maritime traffic safety.
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Kim, Jieun, Hongki Sung, Kyoosoo Cheong, Tae-Hoon Kim und Junhee Youn. „UAV 2D Path Planning Considering Ground Suitability for Flying Safety in Digital Twin“. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-4-2024 (21.10.2024): 269–74. http://dx.doi.org/10.5194/isprs-archives-xlviii-4-2024-269-2024.
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Abstract. The utilization of various UAVs such as facility inspection and delivery is increasing. Ensuring safety in carrying out various UAV missions is an important issue related to human and property damage. Safe operation of UAVs flying autonomously along pre-located routes requires safe route planning to prevent collisions between aircraft in consideration of ground and air obstacles. Pass flight is also essential to minimize damage in the event of a crash. This paper deals with the optimal UAV 2D routing plan considering ground compatibility for flight safety. High ground compatibility here means that the damage caused by the crash is less than when it is not. In this paper, we first defined dynamic and static obstacles. Next, we derived ground compatibility considering dynamic and static obstacles. We used estimation algorithms and land use data to calculate ground compatibility values for flight safety, and through experiments, we calculated an optimal 2DUAV route plan for flight safety.
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Li, Shuo, Fei Teng, Geyang Xiao und Haoran Zhao. „Distributed Optimization-Based Path Planning for Multiple Unmanned Surface Vehicles to Pass through Narrow Waters“. Journal of Marine Science and Engineering 12, Nr. 8 (23.07.2024): 1246. http://dx.doi.org/10.3390/jmse12081246.
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Safety and efficiency are important when Unmanned Surface Vehicles (USVs) pass through narrow waters in complex marine environments. This paper considers the issue of path planning for USVs passing through narrow waterways. We propose a distributed optimization algorithm based on a polymorphic network architecture, which maintains connectivity and avoids collisions between USVs while planning optimal paths. Firstly, the initial path through the narrow waterway is planned for each USV using the narrow water standard route method, and then the interpolating spline method is used to determine its corresponding functional form and rewrite the function as a local cost function for the USV. Secondly, a polymorphic network architecture and a distributed optimization algorithm were designed for multi-USVs to maintain connectivity and avoid collisions between USVs, and to optimize the initial paths of the multi-USV system. The effectiveness of the algorithm is demonstrated by Lyapunov stability analysis. Finally, Lingshui Harbor of Dalian Maritime University and a curved narrow waterway were selected for the simulation experiments, and the results demonstrate that the paths planned by multiple USVs were optimal and collision-free, with velocities achieving consistency within a finite time.
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Belchior, J. C., und J. P. Braga. „A route to inversion for rotational collisions using hard shape potentials“. Chemical Physics 205, Nr. 3 (Mai 1996): 401–6. http://dx.doi.org/10.1016/0301-0104(95)00428-9.
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Zhou, Shibo, Zhizheng Wu und Lüzhen Ren. „Ship Path Planning Based on Buoy Offset Historical Trajectory Data“. Journal of Marine Science and Engineering 10, Nr. 5 (15.05.2022): 674. http://dx.doi.org/10.3390/jmse10050674.
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In the existing research on the intelligent navigation of ships, navigation route planning often regards light buoys as fixed obstructions. However, due to factors such as water ripples, the position of the buoys keeps periodically changing. If the buoys are set to a fixed range of avoidance areas in the process of ship navigation, it is easy to allow a collision between the ship and the light buoys. Therefore, based on historical motion trajectory data of the buoys, a SARIMA-based time-series prediction model is proposed to estimate the offset position of a given buoy in a specified time. Furthermore, the collision-free path planning approach is presented to dynamically recommend an accurate sailing path. The results of the simulation experiment show that this method can effectively deal with collisions of ships caused by the offset position of the light buoys during the navigation of the large and low-speed autonomous ships.
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Ashraf, Adnan, Amin Majd und Elena Troubitsyna. „Online Path Generation and Navigation for Swarms of UAVs“. Scientific Programming 2020 (11.01.2020): 1–14. http://dx.doi.org/10.1155/2020/8530763.
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With the growing popularity of unmanned aerial vehicles (UAVs) for consumer applications, the number of accidents involving UAVs is also increasing rapidly. Therefore, motion safety of UAVs has become a prime concern for UAV operators. For a swarm of UAVs, a safe operation cannot be guaranteed without preventing the UAVs from colliding with one another and with static and dynamically appearing, moving obstacles in the flying zone. In this paper, we present an online, collision-free path generation and navigation system for swarms of UAVs. The proposed system uses geographical locations of the UAVs and of the successfully detected, static, and moving obstacles to predict and avoid the following: (1) UAV-to-UAV collisions, (2) UAV-to-static-obstacle collisions, and (3) UAV-to-moving-obstacle collisions. Our collision prediction approach leverages efficient runtime monitoring and complex event processing (CEP) to make timely predictions. A distinctive feature of the proposed system is its ability to foresee potential collisions and proactively find best ways to avoid predicted collisions in order to ensure safety of the entire swarm. We also present a simulation-based implementation of the proposed system along with an experimental evaluation involving a series of experiments and compare our results with the results of four existing approaches. The results show that the proposed system successfully predicts and avoids all three kinds of collisions in an online manner. Moreover, it generates safe and efficient UAV routes, efficiently scales to large-sized problem instances, and is suitable for cluttered flying zones and for scenarios involving high risks of UAV collisions.
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Sevigny, Jennifer, Amanda Summers, Glen Kalisz und Kelly McAllister. „Identification of Elk-vehicle incident hotspots on state route 20 in Washington State“. Landscape Ecology 36, Nr. 6 (04.04.2021): 1685–98. http://dx.doi.org/10.1007/s10980-021-01238-2.
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Abstract Context Identifying risk zones for wildlife-vehicle incidents is essential for creating effective mitigation efforts on major road networks. Wildlife-vehicle collision data are often used to identify hotspot areas without consideration of species spatial distributions. Objectives Evaluating both can reveal spatiotemporal patterns that can improve mitigation success. Methods We summarized elk-vehicle incident (EVI) data on State Route 20 (SR 20) in Washington State between 2012 and 2019. We also collared 23 elk residing in the vicinity of SR 20 and used GPS location data to identify home ranges and road crossings. We compared EVI and elk road crossing data to identify hotspot locations on SR 20 to help inform mitigation. Results Our EVI and elk crossing data had a non-random distribution along a 38 km section of SR 20 associated with the 95% home ranges of 8 female elk sub-herds. We found EVI data alone were an effective indicator of elk spatial distribution and movement in relation to collision hotspots along SR 20. Our results also indicated a strong association between elk crossings and EVIs by milepost. While the spatial distribution of elk sub-herds was a good predictor of EVI risk zones, EVI frequency was not associated with an increase in elk population. Conclusions Classifying EVI and road crossing distributions as high risk zones is the first step preceding mitigation and protection measures to prevent elk-vehicle collisions. Specific identification of hotspots will result in more effective and successful installations of high cost mitigation efforts such as wildlife crossing structures.
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Жук, А. С. „Iterative method for ship motion planning in unpredictable navigational environment“. MORSKIE INTELLEKTUAL`NYE TEHNOLOGII)</msg> 1, Nr. 3(61) (27.08.2023): 179–87. http://dx.doi.org/10.37220/mit.2023.61.3.018.
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Рассматривается задача гарантированного предотвращения столкновений судов на неограниченном горизонте планирования в условиях непредсказуемого движения судов-целей. Множества достижимости судов-целей с учетом зоны навигационной безопасности определяют области возможных столкновений. Безопасные управления определяются в пространстве скоростей в виде совокупности векторов скорости управляемого судна. Гарантированное предотвращение всех возможных столкновений достигается выбором управления, ведущего за пределы областей возможных столкновений каждого судна-цели. Информация о движении судов-целей ограничена координатами и курсом в текущий момент времени. Суда-цели движутся непредсказуемым образом, но имеют динамические ограничения. Обеспечение безопасности плавания на неограниченном горизонте планирования в условиях непредсказуемости движения судов-целей является приоритетной задачей управления судном. Предварительный маршрут перехода требует коррекции в зависимости от текущей навигационной обстановки. Предлагаемый итеративный метод планирования движения судна в реальном времени обеспечивает гарантированное предотвращение столкновений и минимизирует отклонения от предварительного маршрута перехода. Ожидаемое движение судна-цели определяется на основе текущих параметров. Множества достижимости судов-целей остаются ограниченными в пространстве скоростей даже при увеличении горизонта планирования до бесконечности. Множества достижимости судов-целей дополняются зоной навигационной безопасности и образуют области возможных столкновений. Управления, приводящие вектор скорости управляемого судна за пределы области возможных столкновений в пространстве скоростей, гарантированно предотвращают столкновения даже в условиях непредсказуемости движения судов-целей. Гарантированно безопасные состояния управляемого судна зависят от множеств достижимости судов-целей. Выполненные исследования способствуют совершенствованию перспективных для практического применения в современных навигационных комплексах методов управления судном. The problem of guaranteed prevention of ship collisions on an unlimited planning horizon under conditions of unpredictable motion of target ships is considered. The reachable sets of target ships, taking into account the navigational safety zone, determine the areas of possible collisions. Safe controls are defined in the speed space as a set of speed vectors of the controlled vessel. Guaranteed avoidance of all possible collisions is achieved by choosing a control that leads outside the areas of possible collisions of each target ship. Information about the movement of target ships is limited to the coordinates and course at the current time. Target ships move in unpredictable ways, but have dynamic limitations. Ensuring the safety of navigation on an unlimited planning horizon in the conditions of unpredictable movement of target ships is a priority task of ship handling. The preliminary passage route requires correction depending on the current navigation situation. The proposed iterative real-time ship motion planning method provides guaranteed collision avoidance and minimizes deviations from the preliminary passage route. The expected motion of the target vessel is determined based on the current parameters. The reachable sets of target ships remain bounded in speed space even as the planning horizon increases to infinity. The reachable sets of target ships are supplemented by a navigational safety zone and form areas of possible collisions. Controls that bring the speed vector of the controlled vessel beyond the limits of the area of possible collisions in the speed space are guaranteed to prevent collisions even in conditions of unpredictable motion of target ships. The guaranteed safe states of the controlled ship depend on the reachable sets of the target ships. The performed research contributes to the improvement of ship control methods that are promising for practical use in modern navigation systems.