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The western Alpine belt is the focal point of moderate but constant seismic activity. Numerous geodynamic and seismological studies underline the many scientific questions linked to Alpine dynamic processes and the associated rate of deformation resulting from late continental collision phases, and the assessment of seismic hazard and its associated risks. Seismic monitoring in the northern French Alps was launched in 1987 with the installation of the first seismological network, hosted by the Earth Science Observatory at Grenoble Alpes University. Since then, the network has been updated over the years, keeping pace with technical developments in seismic instrumentation, monitoring and data management. The homogenization of information described in this scientific data paper is motivated by the need for a single instrumental seismic catalogue, consisting in arrival times picks and hypocenters using the same velocity model. The final catalogue SISMalp-1987–2023 (CC-BY-4.0) contains 50,822 weak-to-moderate earthquakes with local magnitude between −1.8 and 5.0; it can serve as a basis for all general seismotectonic and risk assessment studies in the region. [ABSTRACT FROM AUTHOR]

This work addresses the issue of multi-ship collision avoidance decision-making complex encounter situations, and proposes a novel velocity varying-steering collision avoidance method based on an improved particle swarm optimization (IPSO) algorithm. The proposed method establishes a limited range based on the International Regulations for Preventing Collisions at Sea (COLREGs) and creates a multi-objective model, in which the collision risk of ships, the energy loss caused by velocity varying and the voyage loss caused by steering are taken into account. To obtain an optimal solution of the multi-objective model, an IPSO is introduced to determine the feasible solution domain for ship collision avoidance decision making(CADM). The proposed CADM is validated by numerical simulations and navigation simulator. The results indicate that the recommended velocity and course can effectively remove the risk of collision between the ship and target ships. [ABSTRACT FROM AUTHOR]

The influence of harsh Arctic environmental factors has caused ship–ice collision accidents to become the main threat faced by navigating ships. It is necessary to quantify the causation of ship accidents and perform effective risk management and control measures to ensure ship navigation safety. This study proposes a Bayesian network (BN) model-based risk analysis method for ship–ice collision accidents, which is used to quantitatively analyze the key risk factors and primary risk causation paths of ship accidents. First, the fault tree analysis (FTA) method is proposed to constructing the BN structure model, and the BN parameter solution method is further established. Consequently, a triangular fuzzy and defuzzification method is developed to quantify uncertain expert knowledge. Then, the BN inference method is used to analyze the collision risk causation where the North Atlantic and Arctic waters meet. The results indicate that the main risk factors in Arctic waters come from the environment. There are four primary risk causation paths; the proposed management and control measures of the risk causation paths (A), (B), (C), and (D) can effectively reduce the navigation risk by 29.95%, 9.98%, 25.05%, and 3.99%, respectively; the combination of these four measures can reduce the navigation risk by 54.63%.The proposed method has positive guiding significance for ensuring the safety of ship navigation in Arctic waters. [ABSTRACT FROM AUTHOR]

Ensuring the safety of Arctic shipping and preserving the Arctic ecological environment are emerging as key challenges in the shipping sector. Ship collisions and getting trapped in ice are frequently occurring under dynamic ice conditions due to the Arctic environment, making research on ship navigation in Arctic routes significant. Leveraging ship networking technology, we developed an intelligent microscopic model which considered factors such as the future motion trends of multi-ships in front and the influence of pack ice, and carried out a stability analysis of the model utilizing linear and nonlinear methods. Additionally, the accuracy of the theoretical results was further validated through simulation experiments with diverse scenarios. The conclusions manifest that the model can magnify the anti-disturbance ability of traffic flow. Additionally, the problem of energy consumption due to ship speed is explored, and it is determined that the model has a positive intention in reducing speed fluctuations and ship energy consumption. This paper highlights the potential of intelligent microscopic models in studying the safety and sustainability of Arctic shipping routes, providing targeted initiatives to improve safety, efficiency, and sustainability in Arctic shipping. [ABSTRACT FROM AUTHOR]

This study aims to enhance the safety and efficiency of port navigation by reducing ship collision accidents, minimizing environmental risks, and optimizing waterways to increase port throughput. Initially, a three-dimensional map of the port's waterway, including data on water depth, rocks, and obstacles, is generated through laser radar scanning. Visual perception technology is adopted to process and identify the data for environmental awareness. Single Shot MultiBox Detector (SSD) is utilized to position ships and obstacles, while point cloud data create a comprehensive three-dimensional map. In order to improve the optimal navigation approach of the Rapidly-Exploring Random Tree (RRT), an artificial potential field method is employed. Additionally, the collision prediction model utilizes K-Means clustering to enhance the Faster R-CNN algorithm for predicting the paths of other ships and obstacles. The results indicate that the RRT enhanced by the artificial potential field method reduces the average path length (from 500 to 430 m), average time consumption (from 30 to 22 s), and maximum collision risk (from 15 to 8%). Moreover, the accuracy, recall rate, and F1 score of the K-Means + Faster R-CNN collision prediction model reach 92%, 88%, and 90%, respectively, outperforming other models. Overall, these findings underscore the substantial advantages of the proposed enhanced algorithm in autonomous navigation and collision prediction in port waterways. [ABSTRACT FROM AUTHOR]

Every year, fires aboard roll-on roll-off (ro-ro) ships result in costly damage to ships and their cargo and, fortunately less frequently, in tragic loss of life. On the other hand, statistical studies have shown that a large proportion of major fire accidents originated in the vehicle decks. To improve the issue of vehicle-deck fires on board ro-ro ships, a performance-based simulation tool was developed to quantify the consequences of these fires on people, ship, and cargo. This tool combines a deterministic computational fluid dynamics model to assess the fire consequences in the vehicle decks and open areas of the ship; a stochastic network model in the accommodation spaces; and a deterministic evacuation model to evaluate the consequences of fire to people on board. This article briefly presents the numerical tools used and their extension to ro-ro ships, then the results obtained for selected fire scenarios on two generic ro-ro ships, varying the location of the fire source, wind conditions, and including one accidental situation due to a loss of integrity of the insulation at the ceiling of the deck from which the fire originated and one scenario where some openings of this deck were closed. People evacuation was simulated for the accidental scenario. Fire consequences are further evaluated in terms of human survivability, in compliance with the life safety performance criteria of the International Maritime Organization, damage to the ship and cargo. A qualitative comparison with reported accident data is presented to assess the consistency of model results. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to contribute towards establishing procedures of assessment of the fire safety of Ro–Ro ship cargo spaces, by employing suitable design fires. Data collected from fire experiments involving vehicles are utilized in order to deduce representative heat release rates for common types of passenger cars and heavy goods vehicles (HGVs). An existing mathematical scheme for generating parametric heat release rate curves is extended for handling vehicle fire scenarios. The methodology is demonstrated through a case study. In particular, the Fire Dynamics Simulator (FDS) code is used for investigating fire propagation on the vehicle deck of a Ro–Ro ship, initiated from a single HGV. On this deck are assumed to be transported a combination of cars and HGVs. The evolution of the fire is assessed assuming different ventilation conditions. The circumstances for spreading to adjacent vehicles are examined. Human survivability and the time that the deck remains accessible are evaluated by considering the International Maritime Organization (IMO) life safety performance criteria. [ABSTRACT FROM AUTHOR]

This study investigates the sensitivity of the Calcasieu Lake estuarine region to channel deepening in southwest Louisiana in the USA. We test the hypothesis that the depth increase in a navigational channel in an estuarine region results in the amplification of the inland penetration of storm surge, thereby increasing the flood vulnerability of the region. We run numerical experiments using the Delft3D modeling suite (validated with observational data) with different historic channel depth scenarios. Model results show that channel deepening facilitates increased water movement into the lake–estuary system during a storm surge event. The inland peak water level increases by 37% in the presence of the deepest channel. Moreover, the peak volumetric flow rate increases by 291.6% along the navigational channel. Furthermore, the tidal prism and the volume of surge prism passing through the channel inlet increase by 487% and 153.3%, respectively. In our study, the presence of the deepest channel results in extra 56.72 km2 of flooded area (approximately 12% increase) which is an indication that channel deepening over the years has rendered the region more vulnerable to hurricane-induced flooding. The study also analyzes the impact of channel deepening on storm surge in estuaries under different future sea-level rise (SLR) scenarios. Simulations suggest that even the most conservative scenario of SLR will cause an approximately 51% increase in flooded area in the presence of the deepest ship channel, thereby suggesting that rising sea level will cause increased surge penetration and increased flood risk. [ABSTRACT FROM AUTHOR]

This study proposed a safety supervision tool to HRA-based monitoring of ship maintenance operations via a digital platform. It is conceptualized to assist safety supervisors in the best proactive measures along with maintenance works onboard ships. The tool refers the marine maintenance and operations human reliability analysis (MMOHRA) concept. Moreover, it facilitates the timely and consistently practice of MMOHRA. Indeed, it accurately identifies critical tasks and associate recovery acts. Fundamentally, a rule-based mechanism supported with relation matrix response to general task type selection, EPCs' assignment, and human error probability (HEP) calculation, respectively. Then, the system automatically calculates, visualizes and manages HEP values of operation steps. Consequently, this study digitalizes maritime HRA investigations particular to maintenance operations. The proposed tool, compliance with the relevant sections of updated inspection regimes such as SIRE 2.0 and DryBms, has very high utility to effectively control human element onboard. This study also enables a further research potential to conduct an extended human reliability database in ship fleet level. [ABSTRACT FROM AUTHOR]

Predicting and assessing the ship–ship collision possibility in waters are important for discussions on ship traffic safety. The geometric number of collision candidates is one of the most commonly used indexes for representing the frequency of multi-ship encounters that have potential collisions. It has often been estimated for ship traffic in a delimited area based on existing concepts. However, to discuss ship traffic safety in wide-congested waters where ships navigate along various courses and various ship encounters occur, a comprehensive understanding of potential collisions corresponding to all encounter characteristics, such as the encounter angle and location, is necessary. This paper proposes a method, called a "mesh-based estimation method," to calculate the geometric number of collision candidates. It can deal with various encounter angles by introducing a computational mesh to comprehensively assess potential collisions in wide-congested waters. The validation of the method is conducted by applying it to simple ship traffic and comparing the calculated result with a result calculated based on a conventional approach. In addition, the method is applied to traffic data of AIS-equipped ships navigating in Tokyo Bay in Japan to show locations that have potential collisions based on the encounter angles. [ABSTRACT FROM AUTHOR]

Telemanipulation in power stations commonly require robots first to open doors and then gain access to a new workspace. However, the opened doors can easily close by disturbances, interrupt the operations, and potentially lead to collision damages. Although existing telemanipulation is a highly efficient master–slave work pattern due to human-in-the-loop control, it is not trivial for a user to specify the optimal measures to guarantee safety. This paper investigates the safety-critical motion planning and control problem to balance robotic safety against manipulation performance during work emergencies. Based on a dynamic workspace released by door-closing, the interactions between the workspace and robot are analyzed using a partially observable Markov decision process, thereby making the balance mechanism executed as belief tree planning. To act the planning, apart from telemanipulation actions, we clarify other three safety-guaranteed actions: on guard, defense and escape for self-protection by estimating collision risk levels to trigger them. Besides, our experiments show that the proposed method is capable of determining multiple solutions for balancing robotic safety and work efficiency during telemanipulation tasks. [ABSTRACT FROM AUTHOR]

We present an integrated mathematical model and its implementation in the form of a software and information complex developed for joint modeling of the spread of dangerous fire factors and spontaneous evacuation of people from premises of complex configuration. The propagation of fire, heat, and smoke is modeled based on the principle of cellular automata. To simulate the evacuation process, we have developed and used a multiagent model that takes into account the physical characteristics and behavior of people during collisions. [ABSTRACT FROM AUTHOR]

The stopping performance of ships is important to avoid collisions at sea during an emergency. To ensure sufficient stopping performance, stopping tests were performed in a full-scale trial. However, it has been pointed out that initial disturbances, such as slight ship motions represented by heading deviation, hull lateral velocity, and yaw rate, which occur immediately after the start of the stopping test, have a significant influence on the stopping performance by the propeller reverse rotation. In this study, we investigate the influence of a slight initial disturbance on the stopping performance by tank tests and stopping simulations, and discuss the standard for acceptable initial disturbances in the stopping test. The results show that the track reach ( R T ) index is less susceptible to initial disturbances than the side reach and head reach indices. The influence of the initial disturbance on R T is closely related to the course stability of the ship. In the ballast load condition with excellent course stability, the influence of the initial disturbance on R T is small. In contrast, in the full load condition with poor course stability, the influence of the initial disturbance is large, resulting in more variations of R T . Based on the simulation results, a standard for acceptable initial disturbances is presented for a bulk carrier. [ABSTRACT FROM AUTHOR]

Collision avoidance path planning is still one of the essential problems in the design and application of an intelligent maritime navigation system. Its main obstacle is how to determine effective and cooperative collision avoidance maneuvers within a multi-ship encounter situation. By deconstructing a multi-ship encounter, this study adopted ship domain around target ships to assess the collision danger that own ship should avoid. Subsequently, the fitness function that has multiple dynamic obstacle constraints was designed in a two-dimensional map. Based on DE algorithm, a path-planning method was developed to compute collision-free and optimal navigation paths for ships. Simulation results show that the algorithm can generate a safe and suitable path from each perspective in a multi-ship encounter. The results also validate the practicality of the generated paths, consistency of the algorithm outputs and performance of the algorithm. It would be expected to provide a reference for collision avoidance decision making as well as contribute to the development of autonomous navigation systems. [ABSTRACT FROM AUTHOR]

Artificial intelligence is an enabling technology for autonomous surface vehicles, with methods such as evolutionary algorithms, artificial potential fields, fast marching methods, and many others becoming increasingly popular for solving problems such as path planning and collision avoidance. However, there currently is no unified way to evaluate the performance of different algorithms, for example with regard to safety or risk. This paper is a step in that direction and offers a comparative study of current state-of-the art path planning and collision avoidance algorithms for autonomous surface vehicles. Across 45 selected papers, we compare important performance properties of the proposed algorithms related to the vessel and the environment it is operating in. We also analyse how safety is incorporated, and what components constitute the objective function in these algorithms. Finally, we focus on comparing advantages and limitations of the 45 analysed papers. A key finding is the need for a unified platform for evaluating and comparing the performance of algorithms under a large set of possible real-world scenarios. [ABSTRACT FROM AUTHOR]

The intrusion of debris avalanches into reservoirs frequently occurs in mountainous regions and is a complex solid-fluid interaction. A coupled discrete element method (DEM) and smooth particle hydrodynamics (SPH) method is developed to forecast the entire process of disaster chains including landslide motion, wave generation, and wave propagation on Kaiding slopes at the Houziyan Reservoir, Sichuan Province, China. The sliding masses are treated as granular assemblies with collisions instead of rigid solid. The simulation results indicate that the maximum velocity of debris avalanches when swarming into the water surface is beyond 30 m/s, and the maximum wave elevation on the watercourse and the maximum run-up wave elevation generated by landslides reach 1867.4 m and 1883.0 m, respectively, and the minimum wave trough is 1822.1 m occurring near opposite bank of landslide. Furthermore, the range of landslide-generated waves is estimated to be approximately a propagation distance of 800.0 m along the axis of the river. The coupled DEM-SPH simulation method provides important inspiration for hazard prevention on reservoir landslides. [ABSTRACT FROM AUTHOR]

Ship collisions caused by navigation officer error significantly threaten the safety of marine navigation. An increased fear of collision for navigation officers in a close-quarters situation (CQS) may lead to failure to perform the prescribed collision-avoidance measures. This study measured the perceived collision risk (PCR) for 30 coast guard navigation officers according to their heart-rate variability in CQSs, then identified the key factors influencing measured PCR values. The PCR was measured in four types of simulated CQS, with two ships approaching each other from 2.5 nautical miles to the point of collision. The maximum PCR bearing was identified at a relative bearing of 135° based on the "own ship." Multiple regression analysis showed that the navigator's personality factors, i.e., their onboard career and license rating, negatively (−) influenced the 95% confidence level. However, navigator age did not have significant effects on PCR. This investigation of PCR factors can help novice navigators avoid collisions due to fear or panic in a CQS with a target ship. [ABSTRACT FROM AUTHOR]

This paper presents an automatic collision avoidance algorithm for ships using a deep reinforcement learning (DRL) in continuous action spaces. Obstacle zone by target (OZT) is used to compute an area where a collision will happen in the future based on dynamic information of ships. Agents of DRL detects the approach of multiple ships using a virtual sensor called the grid sensor. Agents learned collision avoidance maneuvering through Imazu problem, which is a scenario set of ship encounter situations. In this study, we propose a new approach for collision avoidance with a longer safe passing distance using DRL. We develop a novel method named inside OZT that expands OZT to improve the consistency of learning. We redesign the network using the long short-term memory (LSTM) cell and carried out training in continuous action spaces to train a model with longer safe distance than the previous study. The bow cross range in collision detection proposed in this paper is effective to COLREGs-compliant collision avoidance. The trained model has passed all scenarios of Imazu problem. The model is also validated by a test scenario which includes more ships than each scenario of Imazu problem. [ABSTRACT FROM AUTHOR]

This paper discusses the rear left-hand occupant's injury during frontal oblique collision with PRESYS software. Based on the simulations among different frontal oblique angles (10 ∼ 50 °) and occupant constraint system models, the injury of rear left-hand dummy are analyzed at an initial collision speed of 50 km/h. It is found that the impact on the occupant's dynamic responses (acceleration and shear forces) by the seat belt is significant and depends upon the oblique angle. With the given vehicle and collision speed, it is observed that the seat belt can effectively reduce the occupant's head acceleration and the neck longitudinal (Fx) shear force if the collision angle is between 10 ° and 20 °. However, the seat belt increases the occupant's head resultant acceleration when the collision angle is between 35 ° and 40 °. In addition, when the collision angle is between 10 ° and 50 °, the seat belt can also effectively reduce the occupant's chest acceleration. At most collision angles, the seat belt can effectively reduce the overall damage of rear row left occupant in frontal oblique collision, but the WIC (Weighted Injury Criterion) value of the rear row dummy with seat belt is still very large at the collision angle below 30 °. Therefore, the restraint system of the rear row occupants needs to be improved. [ABSTRACT FROM AUTHOR]

Autonomous navigation on the open sea involving automatic collision avoidance and route planning helps to ensure navigational safety. To judge whether all target ships (TSs) will pass safely and find the optimal route under multi-ship encounter situations, the relationship between the variations in the own ship (OS) velocity vector after nonlinear course altering motion and the collision avoidance result, which is defined as the collision avoidance mechanism, was analyzed. Methods producing the optimal route were also proposed. First, the static collision avoidance mechanism based on the ship domain and velocity obstacle (VO) was introduced. On that basis, the collision-free course alteration range of the OS, without consideration of the real manoeuvring process, was presented. Second, the ship motion equations and fuzzy adaptive proportion integral derivative (PID) control method were combined to develop a course control system. This system was then used to predict OS motions during the course-altering process. Based on this prediction, TS positions were calculated. Subsequently, the dynamic collision-free course altering ranges for the OS were obtained. Third, a model to compute the optimal route was introduced. Finally, simulations were performed under a situation including six TSs and two static objects, and the shortest collision-free route that satisfies both regulations for preventing collisions and good seamanship was found. [ABSTRACT FROM AUTHOR]

As in terrestrial facilities, safety is one of the most important issue in ships. Vessels navigating in many parts of the world face many different, tough and dangerous navigational risks. In this context, twenty-three fundamental risks which are frequently encountered in ship navigation were considered in this study and examined by an FMEA-based TOPSIS approach under single valued neutrosophic sets. Because of the lack of data in the literature, the opinions of the experts (Masters) who have many years of experience in the sector were taken. As a result of the study, extreme weather conditions, injury of crew, loss of input of sensory equipment (depth, gyro, speed etc.), struck by ropes, exposure to high speed machineries under high pressures, loss of maneuverability are very important among these risks. Considering these risks, corrective-preventive action plans and managerial implications for ship navigation have been presented. Consequently, the results of this study have an important warning and solution recommendation regarding ship navigation risks. [ABSTRACT FROM AUTHOR]

This study proposes a multi-ship collision avoidance and route generating algorithm based on the general requirements of the International Regulations for Preventing Collisions at Sea (COLREGs) and the artificial potential field (APF) method. The velocity potential field is used as the field function of APF method. The algorithm consists of two modes, the course-changing and the track-keeping modes based on the velocity potential of vortex and dipole, respectively. The course-changing mode guides the ship to turn away from the obstacles according to the vector field of vortex potential. The track-keeping mode steers the ship back to and along on a pre-designed track in accordance with the vector field of dipole potential. The data of distance to the closest point of approach (DCPA), time to the closest point of approach (TCPA) and bearing angle evaluated from a maneuvering simulation are the acquired parameters of the proposed collision avoidance algorithm. The algorithm is straightforward and very simple to implement, and is suitable for the real time and distributed intelligent collision avoidance system. Simulation results indicate that the anti-collision formulation can avoid collision safely with the desired distance and indicate that the algorithm proposed can work effectively. [ABSTRACT FROM AUTHOR]

We analyzed data from traffic counters installed on 143 Czech roads (motorways and primary roads) which precisely indicated current traffic volume during occurrences of ungulate-vehicle collisions (UVC). One thousand nine hundred ninety-five UVCs were identified over the period 2009–2015 on these 143 road segments. The overall range of annual average daily traffic (AADT) values, for the respective roads, was between 1547 and 78,320 AADT (vehicles/day). Almost 80% of UVC took place at volume lower than 1000 vehicles/h. We demonstrate that traffic volume has a different distribution during the day when compared with UVC distribution. The highest relative risk of UVC was identified for traffic up to 750 vehicles/h. The risk of UVC varied over the course of the year as it was influenced by ungulate locomotory activity. We concluded that the AADT, representing average annual daily traffic, does not accurately represent the actual traffic volume which is present during the night hours, where the majority of UVC usually occur. Therefore, there is a danger that UVC risk modeling, relying on AADT, will be distorted. [ABSTRACT FROM AUTHOR]

Water mist-based fire-extinguishing systems are gaining acceptance for the protection of ship machinery spaces. The use of simulation tools presents a great potential for taking a performance-based design (PBD) approach to these fire scenarios. The Fire Dynamics Simulator (FDS) is the most frequently used and validated fire modeling software; however, studies of low-pressure water mist fire suppression modeling in ship engine rooms are rare. This paper contributes to the current literature by using the FDS to model a series of fire suppression scenarios defined by the International Maritime Organization (IMO) Circulars, including spray and pool fires with heptane and diesel oil, as well as exposed and obstructed fires. The simulation results are compared to data from full-scale tests conducted at recognized fire testing laboratories. Furthermore, an analysis of both the experimental and model uncertainties is carried out to assess the simulations performance. In general, a good agreement in compartment temperature evolution and fire extinguishing time is found for the modeled fire scenarios. The results support the application of FDS in a PBD approach for the design of water mist fire extinguishing systems for machinery spaces in ships. In this way, designers and engineers could model different machinery volumes and nozzles spacings that differ from those prescribed for a one story square engine room of the IMO, and, thus, predict the evolution of temperatures and extinguishing times for get the authorities approval. [ABSTRACT FROM AUTHOR]

Presentations and workshops on disaster cases for professional development purposes are popular among engineers. Despite common use of such case based learning, there has been only limited investigation into this practice in a hazardous industry context. Based on the literature on case based learning, this paper presents findings from five workshops on the causation of the Überlingen mid-air aircraft collision in 2002 with 43 Australian pipeline project personnel. Using Kolb's four-stage model of experiential learning, the analysis shows how the case offers a concrete experience, an opportunity for reflective observation and abstract conceptualization in group discussion, and space to experiment with and apply lessons to participants' own sector completing the learning cycle. Participants were able to take both lessons about principles of organizational safety and technical aspects, suggesting far greater potential for this training approach than acknowledged in previous studies. We conclude with observations about what makes for an effective case, and how to best structure and facilitate the learning experience. [ABSTRACT FROM AUTHOR]

Telecom systems for ships and offshore plants used to be tools for long-distance communication in the past. Today, telecom systems combined with evolving IT ensure safety, accident prevention and cost saving for ships and offshore plants. In the future, all systems will be managed and controlled by telecom systems. Yet, the IMO and Classification Societies have neither revised nor amended the requirements and certification concerning telecom systems for decades. The failure to establish a standardized scheme applicable to telecom systems hinders ships and offshore plants from adopting advanced next-generation technologies widely used on land. Thus, unstandardized telecom systems are manufactured and installed for different user demands. Consequently, complicated interfaces impede the scalability and compatibility between telecom systems. Ships and offshore plants require advanced stability and diversity compared to their onshore counterparts. Unless the communication systems for ships and offshore plants are duly verified before use, serious adverse effects including marine accidents may ensue. This paper proposes a method of standardization to implement safe, scalable and general-purpose telecom systems for ships and offshore plants. The standardization of communication systems for ships and offshore plants facilitates the simplification and systematization of interfaces, and thus maximizes system inter-operability. Also, ships and offshore plants should adopt the standardized communication systems to enhance data reliability. This paper demonstrates the superior stability and performance of the proposed standardized communication system compared to the existing systems. Moreover, it proves the proposed system ensures the stable performance and fast data processing even in emergency. The standardized system for ships and offshore plants is a requisite for quality improvement, cost saving and stable performance. The findings of this paper are applied to the Smart Ship Solution for standardized integrated communication systems for containers, VLCC and LNG. Also, this paper analyzes the strengths and weaknesses of telecom systems configuration in TMS for offshore plants. In addition, it experimentally demonstrates the advantages of the proposed standardization of telecom systems in light of processing time and system operation cost. [ABSTRACT FROM AUTHOR]

Presently, ships are organic assets to be co-managed at sea and on land together, going beyond the independent maritime structures. In addition, R&D on marine systems technologies is actively under way. Smart ship is cited as one of the key ship technologies responsible for the future along with economic ship routing and unmanned ship concepts. Conventional navigation and communication systems in ships were tools for distance communication. Recently, all the systems handling data and information are integrated into navigation and communication systems. Integrated management of navigation and communication systems on one platform is equivalent to integration of all information about a ship, and crucial for future system scalability and further development of ships. The core technologies on ships such as remote management, accident prevention, and security should be developed based on the navigation and communication systems. However, because of institutional and economic constraints, the navigation and communication systems have not been standardized yet. Too many types of cables are connected to the navigation and communication systems in very complicated ways. In this situation, the design and building costs, maintenance costs, and weight of vessels are rapidly increasing. This paper proposes a novel integrated system based on e-TMS for navigation and communication systems. The e-TMS makes the functions of navigation and communication systems shared with the integrated terminal equipment. This paper also proposes a method of integrating navigation and communication systems and analyzes its economic feasibility for reinforcing the competitiveness of ships. The proposed system outperforms the existing TMS system by 34.3% at shortening the processing time for typical types of alarm data used on ships. [ABSTRACT FROM AUTHOR]

Thousands of fatalities are reported from the construction industry every year and a high percentage of them are due to the unsafe worker movements which resulted in falling from heights, transportation accidents, exposure to harmful environments, and striking against or being struck by the moving equipment. To reduce such fatalities, a system is proposed to monitor worker movements on a construction site by collecting their raw spatio-temporal trajectory data and enriching it with the relevant semantic information. To acquire the trajectories, the use of an indoor positioning system (IPS) is considered. Bluetooth beacons are used for collecting spatio-temporal information of the building users. By means of an Android-based mobile application, neighboring beacons' signals are selected, and a geo-localization technique is performed to get the unique pairs of users' location coordinates. After pre-processing this collected data, three semantic enrichment techniques are used to construct semantically enriched trajectories which are as follows: (1) enrichment with the semantic points which maps site location identification to the trajectory points; (2) enrichment with the semantic lines which relies on the speed-based segmentation approach to infer user modes of transportation; (3) enrichment with the semantic region for mapping a complete trajectory on an actual building or a construction site zone. The proposed system will help in extracting multifaceted trajectory characteristics and generates semantic trajectories to enable the desired semantic insights for better understanding of the underlying meaningful worker movements using the contextual data related to the building environment. Generated semantic trajectories will help health and safety (H&S) managers in making improved decisions for monitoring and controlling site activities by visualizing site-zones' density to avoid congestion, proximity analysis to prevent workers collisions, identifying unauthorized access to hazardous areas, and monitoring movements of workers and machinery to reduce transportation accidents. [ABSTRACT FROM AUTHOR]

The automated enforcement systems (AESs), which detect speeding vehicles or vehicles that violate traffic signals, are installed and operated on urban arterial roadways to prevent traffic collisions and reduce injury severity in case of a traffic collision. As it is expensive to install the AES, it will be installed at a site where it is expected to have a great effect. However, as there are no specific guidelines on where it should be installed, it has been installed arbitrarily in high collision concentration locations (HCCLs). The objective of this study is to contribute to the improvement in the efficiency of system operation and budget execution by identifying sites where the enforcement effect of the AES is high, and providing a road manager with the basis of decision-making on system installation. This study classified road sections into clusters based on road environment characteristics and spatial collision occurrence pattern, respectively, and compared collisions statistics and occurrence pattern before and after AES installation to analyze the effect of AES installation. As a result, the study verified that the number of collisions tends to decrease at HCCLs past enforcement sites, while the number of collisions tends to increase at sites where not only red light running but also speeding is enforced after AES installation. In addition, from the perspective of collision severity, it was observed that the severity of collisions was alleviated in most clusters after AES installation. This may be viewed as a positive effect caused by the decrease in vehicle speed due to speeding enforcement. [ABSTRACT FROM AUTHOR]

Underwater gliders, which are profiling autonomous underwater vehicles designed to make oceanographic measurements, are increasingly used in the coastal ocean. As they regularly surface for data transmission, gliders increasingly pose a risk for fast ships. In order to estimate the extent of damage due to collision, 3D finite element simulations of collisions between a glider and a high-speed craft with a glass-fiber reinforced plastic hull are performed. Different collision scenarios such as impact locations, angles of attack and speeds are examined. The results are compared to an analytical solution based on simplifying assumptions. Although both methods reveal consistent results, it is shown that finite element simulations are required to account for the 3D shape of the ship. The results indicate that at ship velocities exceeding 7.5 m/s (14.6 kt) the glider penetrates the ship's hull causing severe damage to its structure. [ABSTRACT FROM AUTHOR]

The time dependency of the survivability of passenger ships in flooding accidents leading to ship's loss is shown to be confined within short times after the flooding initiation. RoRo ferry and cruise type ships demonstrate similar behaviour, though vessel types differ with respect to the subdivision and the flooding process. The presented research is based on numerical simulations of the flooding of two sample passenger ships in collision damages and the estimation of the probability to capsize. The systematic fast character of capsize events is shown to be primarily a consequence of the extent of hull breaches. The IMO regulatory concept for orderly abandonment of damaged passenger ships, in addition to the safe return to port regulatory provisions, are discussed in view of the present results. The timely onboard damage identification by ship's master and the enhancement of the SOLAS survivability requirements for passenger ships appear to be the most effective operational and design measures leading to improved survivability of the ship and to enhanced safety of people onboard. [ABSTRACT FROM AUTHOR]

Deep-water shipwrecks and associated debris often sit on the bottom with relatively little disturbance, except for the natural bio-chemical deterioration. The distribution of shipwreck material can often be calculated mathematically as a function of heading, speed, time, and water depth. The Equation of Site Distribution is a method aimed to better understand deep-water site formation and the wrecking events themselves. With the use of a few relatively simple formulas, key elements of a site can be discovered, as well as greater insight of the overall wrecking event achieved. [ABSTRACT FROM AUTHOR]

The demonstrated utility of underwater gliders as measurement platforms for the open ocean has sparked a growing interest in operating them in shallow coastal areas too. Underwater gliders face additional challenges in this environment, such as strong (tidal) currents and high shipping intensity. This work focuses on the probability of losing a glider through a collision with a ship. A ship density map is constructed for the German Bight from observed ship movements derived from automatic identification system data. A simple probability model is developed to convert ship densities into collision probabilities. More realistic-but also more computationally expensive-Monte Carlo simulations were carried out for verification. This model can be used to generate geographic maps showing the probability of glider loss due to collisions. Such maps are useful when planning glider missions. The method developed herein is also applicable to other types of AUVs. [ABSTRACT FROM AUTHOR]

Conservation and management of the endangered Florida manatee is often centered on reducing mortality caused by watercraft collisions. Lee County, Florida, has led the state in watercraft-related mortality for eight of the last 10 years. This county is of particular concern as it contains important habitat for manatees, including extensive feeding grounds and an artificial warm-water refuge where more than 900 manatees have been recorded on a single day. Distributional aerial surveys were conducted from April 2007 through April 2009 over Lee County waters. Surveys yielded higher numbers of manatees than previously observed in this area. Using GIS methodology, kernel density analysis illustrated seasonal changes in distribution patterns and highlighted areas where manatees were most densely clustered. For example, during summer months, manatees were widely distributed throughout the survey area, with high-density areas associated with seagrass beds. During winter months, manatees were densely clustered at warm-water sites and over feeding grounds within close distance of these sites. These seasonal distribution patterns coincide well with speed zone designations. Counts and distributions of manatees were made available, almost immediately if necessary, to local marine law enforcement in an attempt to focus resources toward reducing manatee-watercraft collisions. Future studies should implement similar communication strategies to improve conservation efforts. [ABSTRACT FROM AUTHOR]

Early Paleozoic paleomagnetic data from NW Argentina and Northern Chile have shown large systematic rotations within two domains: one composed of the Western Puna that yields very large (up to 80°) counter-clockwise rotations, and the other formed by the Famatina Ranges and the Eastern Puna that shows (~40°) clockwise rotations around vertical axes. In several locations, lack of significant rotations in younger rocks constrains this kinematic pattern to have occurred during the Paleozoic. Previous tectonic models have explained these rotations as indicative of rigid-body rotations of large para-autochthonous crustal blocks or terranes. A different but simple tectonic model that accounts for this pattern is presented in which rotations are associated to crustal shortening and tectonic escape due to the collision of the allochthonous terrane of Precordillera in the Late Ordovician. This collision should have generated dextral shear zones in the back arc region of the convergent SW Gondwana margin, where systematic domino-like clockwise rotations of small crustal blocks accommodate crustal shortening. The Western Puna block, bordering the Precordillera terrane to the north, might have rotated counterclockwise as an independent microplate due to tectonic escape processes, in a fashion similar to the present-day relationship between the Anatolia block and the Arabian microplate. [ABSTRACT FROM AUTHOR]

new U-Pb SHRIMP age of 551 ± 4 Ma on a mylonitic porphyry that intruded into the Sierra Ballena Shear Zone (Southernmost Dom Feliciano Belt, Uruguay) and a review of relevant published data make possible a more refined correlation and reconstruction of Brasiliano/Pan-African transpressional events. Paleogeographic reconstruction, kinematics and timing of events indicate a connection between the shear systems of the Dom Feliciano and Kaoko Belts at 580-550 Ma. Sinistral transpression recorded in shear zones accommodates deformation subsequent to collision between the Congo and Río de la Plata Cratons. The correlation is strengthened by the similarity of magmatic and metamorphic ages in the Coastal Terrane of the Kaoko Belt and the Punta del Este Terrane of the Dom Feliciano Belt. This post-collisional sinistral transpression brought these units near to their final position in Gondwana and explains the different evolution at 550-530 Ma. While in the Kaoko Belt, an extensional episode resulted in exhumation as a consequence of collision in the Damara Belt, in the Dom Feliciano Belt, sinistral transpression occurred associated with the closure of the southern Adamastor Ocean due to Kalahari-Río de la Plata collision. [ABSTRACT FROM AUTHOR]

Abstract  This study was initiated due to the lack of experimental data on ship collisions. The feasibility of model-scale ship collision experiments was examined and a series of model-scale ship collision experiments is presented. The theoretical background for the analysis of experiments is given together with the principles of scaling. Proper scaling should assure physical similarity to the large-scale experiments conducted in the Netherlands. The Froude scaling law was followed, resulting in the improper scaling of some forces: the effects of this are discussed. The study concentrates on the dynamics of collisions. The structural response, properly scaled from the large-scale experiments, was modelled using polyurethane foam as the ship’s side structure. The collision process was analysed and the results of model-scale tests, large-scale experiments, and a simple analytical model were compared, showing that there was both quantitative and qualitative agreement in the results of the experiments conducted at different scales. The analytical model yielded good quantitative assessment of the deformation energy. [ABSTRACT FROM AUTHOR]

A total of 23 whale sharks were identified over a 5 d period in the Arta Bay region of the Gulf of Tadjora, Djibouti. Most of the sharks aggregating in this area were small (<4 m TL) males. Individuals were identified using photographs of distinctive scars and spot and stripe patterns on the sides of the animals. Of these, 65% had scarring that was attributable to boat or propeller strikes. Most of the whale sharks we encountered were feeding on dense accumulations of plankton in shallow water just off (10–200 m) the shoreline. This food source may account for the aggregation of sharks in this area. One 3 m male shark was tagged with an ARGOS (Splash) satellite tag for 9 d. During this time the shark traversed to the shoreline on the opposite side of the Gulf (a distance of 14 km) and then returned to the Arta Bay area before retracing his path to the other shore. The shark spent most of the daylight hours at the surface, while at night dives were more frequent, deeper and for longer durations. [ABSTRACT FROM AUTHOR]

Survey work was undertaken on the wreck of the French frigate La Surveillante, part of a planned invasion force of Ireland in an attempt to overthrow English rule, which was lost in Bantry Bay off the southwestern coast of Ireland in January 1797. Some of the published background history of French frigates describes a similar type to La Surveillante. Archaeological investigations found that preservation on the wreck is exceptional for Irish waters and that its study offers a valuable insight into the structure, morphology, and role of the frigate in the later part of the 18th century. [ABSTRACT FROM AUTHOR]

Recent marine survey programs have generated a GIS (geographic information system) distribution of historic wreck sites around the coast of Northern Ireland. These data lead to an understanding of the nature and extent of submerged cultural resources and provide statistical information on the spatial and temporal distribution of historic wrecks, allowing for the reconstruction of past maritime activity. This is important baseline data used for the production of integrated research and management plans for the protection of the resources. [ABSTRACT FROM AUTHOR]

The best strategy for collision avoidance under emergency conditions is to maximize wrt the controls the timewise minimum distance between the host ship and the intruder ship. In a restricted waterway area, two main constraints must be satisfied: the lateral deviation of the host ship from the original course is to be contained within certain limits; the longitudinal distance covered by the host ship is to be subject to a prescribed bound. At the maximin point of the encounter, the time derivative of the relative distance vanishes; this yields an inner boundary condition (orthogonality between the relative position vector and the relative velocity vector) separating the main phases of the maneuver: the avoidance and recovery phases. In this way, the optimal trajectory problem (a Chebyshev problem) can be converted into a Bolza problem with an inner boundary condition. Numerical solutions are obtained via the multiple-subarc sequential gradient-restoration algorithm (SGRA). Because the optimal trajectory is not suitable for real-time implementation, a guidance scheme approximating the optimal trajectory in real time is to be developed. For ship collision avoidance, the optimal trajectory results show that the rudder angle time history has a bang-bang form characterized by the alternation of saturated control subarcs of opposite signs joined by rapid transitions. Just as the optimal trajectory can be partitioned into three phases (avoidance phase, recovery phase, steady phase), a guidance trajectory can be constructed in the same way. For the avoidance and recovery phases, use of decomposition techniques leads to an algorithm computing the time lengths of these phases in real time. For the steady phase, a feedback control scheme is used to maneuver the ship steadily. Numerical results are presented. [ABSTRACT FROM AUTHOR]

The ideal strategy for ship collision avoidance under emergency conditions is to maximize wrt the controls the timewise minimum distance between a host ship and an intruder ship. This is a maximin problem or Chebyshev problem of optimal control in which the performance index being maximinimized is the distance between the two ships. Based on the multiple-subarc sequential gradient-restoration algorithm, a new method for solving the maximin problem is developed. Key to the new method is the observation that, at the maximin point, the time derivative of the performance index must vanish. With the zero derivative condition being treated as an inner boundary condition, the maximin problem can be converted into a Bolza problem in which the performance index, evaluated at the inner boundary, is being maximized wrt the controls. In turn, the Bolza problem with an added inner boundary condition can be solved via the multiple-subarc sequential gradient-restoration algorithm (SGRA). The new method is applied to two cases of the collision avoidance problem: collision avoidance between two ships moving along the same rectilinear course and collision avoidance between two ships moving along orthogonal courses. For both cases, we are basically in the presence of a two-subarc problem, the first subarc corresponding to the avoidance phase of the maneuver and the second subarc corresponding to the recovery phase. For stiff systems, the robustness of the multiple-subarc SGRA can be enhanced via increase in the number of subarcs. For the ship collision avoidance problem, a modest increase in the number of subarcs from two to three (one subarc in the avoidance phase, two subarcs in the recovery phase) helps containing error propagation and achieving better convergence results. [ABSTRACT FROM AUTHOR]

Collisions of vehicles with wildlife pose a serious risk to humans and animals, causing great financial and ecological damage each year. While various mitigation measures have been developed, only a few are economically and logistically feasible. Among these, wildlife warning reflectors arguably enjoy the greatest popularity, although recent studies have shown that they have no long-term impact on wildlife-vehicle collisions or on the behavior of animals along roads. However, belief in their temporary effect on animals and motorists persists among manufacturers and hunters. In our study, we analyzed the reactions of ungulates towards approaching vehicles and motorists towards wildlife near roads, before and after installation of modern multi-colored wildlife warning reflectors. We also tested for a potential habituation effect of both, animals as well as motorists, to the presence of wildlife warning reflectors. In total, we studied animal behavior on 13 study sites during a 12-month study period using thermal cameras before and after wildlife warning reflector installation, also controlling for seasonal variation in animal behavior. Exploratory analyses using linear mixed-effects models (LMM) and generalized linear mixed-effects models (GLMM) evaluated the effect of the reflectors on road crossing events, reactions of animals to vehicles (positive vs. negative; no reaction < alarm < locomotion < flight), flight events, flight initiation distance, and the braking responses of motorists when animals were nearby. Ungulates were more likely to leave the road side area (alarm > locomotion) with reflectors present. However, this effect only lasted 16.5 days und did not influence the risk of a collision with a vehicle. In addition, reflectors did not alter the driving behavior of motorists. We conclude that wildlife warning reflectors are not effective for reducing vehicle collisions with wildlife. [ABSTRACT FROM AUTHOR]