Rescue Ship Research Articles

Artificial neural network infused quasi oppositional learning partial reinforcement algorithm for structural design optimization of vehicle suspension components

Abstract This paper introduces and investigates an enhanced Partial Reinforcement Optimization Algorithm (E-PROA), a novel evolutionary algorithm inspired by partial reinforcement theory to efficiently solve complex engineering optimization problems. The proposed algorithm combines the Partial Reinforcement Optimization Algorithm (PROA) with a quasi-oppositional learning approach to improve the performance of the pure PROA. The E-PROA was applied to five distinct engineering design components: speed reducer design, step-cone pulley weight optimization, economic optimization of cantilever beams, coupling with bolted rim optimization, and vehicle suspension arm optimization problems. An artificial neural network as a metamodeling approach is used to obtain equations for shape optimization. Comparative analyses with other benchmark algorithms, such as the ship rescue optimization algorithm, mountain gazelle optimizer, and cheetah optimization algorithm, demonstrated the superior performance of E-PROA in terms of convergence rate, solution quality, and computational efficiency. The results indicate that E-PROA holds excellent promise as a technique for addressing complex engineering optimization problems.

Numerical Study of Discharge Coefficients for Side-Damaged Compartments

Accurately evaluating the buoyancy and stability of damaged ships, particularly the flow rate of the water inflow through damaged openings, is of great significance for ship rescue and emergency repair. A three-dimensional simplified model of inflow for a ship’s damaged side bulkheads is established using the shear stress transport k-epsilon and volume of fluid (VOF) models by STAR-CCM+. Moreover, the flow rates of water inflow through damaged openings with different shapes, characteristic sizes, and central depths are calculated. Furthermore, the corresponding discharge coefficients are obtained, and the relevant rules are summarized. It was found that the influence of water depth on the coefficient is minimal in these work conditions, but from the perspective of the damaged opening’s characteristic dimensions and shape, the variation in the coefficient is more pronounced. Overall, the triangular opening has a higher coefficient than the circular opening, which in turn is higher than that of the square-damaged opening, and the coefficient decreases as the size of the opening increases. Lastly, empirical formulas for two different methods are provided. The research provides a reference for the rescue repair and buoyancy stability assessment of damaged ships.

Enhancing the Stability of Small Rescue Boats: A Study on the Necessity and Impact of Hydraulic Interconnected Suspensions

Aiming to solve the problem that existing small rescue boats cannot realize the effective and stable rescue of human lives under high sea turbulence conditions, this paper proposes a parallel decoupled hydraulic interconnected suspension system for actual sea state. The system dynamics model is established, and its damping characteristics are analyzed by joint simulation. The results show that compared with the truss-type rescue ship, the suspension system can improve the transverse rocking resistance by 81.5% and the longitudinal rocking resistance by 25.0%, and the system has excellent transverse rocking resistance.

CALCULATION AND OPTIMIZATION OF FORCE AND POWER ON AUTONOMOUS SURFACE VEHICLE (ASV) AS MEANS OF MARINE ACCIDENT RESCUE

The strategic regional position makes Indonesia a world transportation crossing route with various modes of transportation through Indonesian territory to reach other islands, countries, or even continents. For this reason, a solution is needed to reduce the number of fatalities and injuries due to ship accidents that may occur. By reducing the evacuation time to a minimum, it will be possible to minimize the number of casualties and injuries if the ship has an accident. Considering that, in terms of usability and benefits, the Autonomous Surface Vehicle (ASV) can be an alternative as a form of Search and Rescue (SAR) ship. Based on the results of the ASV Ship design that suits these needs, a force and power analysis was carried out in accordance with the applicable theory. Of the 2 designs with a monohull shape and with different hull variations, with the main dimensions of the ASV Sang Nagari (LH=4.55 m, LWL=4.348 m, B=1.272 m, D=0.804 m T=0.45 m) and ASV Sang Nadibumi (LH=4.55 m, LWL=4.311 m, B=1.352 m, D= 0.802 m, T=0.4 m) obtained a displacement of 1.063 tons and a resistance of 1 kN for ASV Sang Nagari and 1.202 tons and a resistance of 2.6 kN for ASV Sang Nadibumi at a standard speed of 10 knots. Based on the results of the force analysis, it is concluded that the two ASVs have 2 forces in static conditions, that is, weight force and upward lift force (FBouyant). Based on the results of the efficiency of ASV Sang Nagari has a higher efficiency of 0.002% with 56.422% than ASV Sang Nadibumi with 56.420%.. The ASV linear model made from linearization has the properties of a controllable and observable, so this model can be applied to navigation and control systems.

Ship Rescue Optimization: A New Metaheuristic Algorithm for Solving Engineering Problems

<p>In recent years, more and more problems in the industry have started to be solved using metaheuristics. In this paper, inspired by the ship maneuvering motion function and the rescue process, we propose ship rescue optimization (SRO) to solve the challenging optimization problem. The ship rescue process can be divided into two types of delayed rescue (large area rescue) and immediate rescue (small rescue) according to the searched person, and we can correspond these two types of rescue behaviors to the search space exploration and exploitation processes, respectively. In this process, SRO simulates the motion process of ship rescue according to the ship maneuvering equation of motion and finally comes up with an optimal position update algorithm. We verified the performance of the proposed algorithm on different dimensions of 57 test functions consisting of CEC2013 and CEC2017 and on three real engineering problems, and compared it with eight current mainstream algorithms. The algorithm proposed in this paper is shown to be robustly applicable in solving challenging optimization problems.</p> <p> </p>

PTSD Among Refugee Rescue Workers: Effects of Compassion Satisfaction and Fatigue on Burnout

Exposure to traumatic life events can affect workers’ prevalence to post-traumatic stress disorder (PTSD) and quality of life. A cross-sectional study was conducted among 126 volunteers and 33 professional rescue workers in the Open Arms rescue ship operating in the Aegean Sea to analyze the effects of stress exposure on the professional quality of life. Volunteers presented more compassion satisfaction and less burnout than professionals. In terms of gender, women showed more secondary traumatic stress and intrusion than men. Finally, burnout can be explained by age, compassion satisfaction, and secondary traumatic-stress. These results show the necessity of tailored interventions for the people who work in trauma contexts.

Intersecting hostilities around the European migration crisis: the case of Carola Rackete and the Sea-Watch 3

ABSTRACT On June 29, 2019, Carola Rackete docked the rescue ship Sea-Watch 3 on the Sicilian island of Lampedusa, in defiance of a ban imposed by Italy's Interior Minister Matteo Salvini. The migrants rescued by the Sea-Watch 3 had been blocked at sea for the previous two weeks, making it to international headlines and sparking a heated debate around sovereignty and humanitarianism in the face of the European migration crisis. On her arrival, Rackete was arrested for refusing to obey a military vessel and aiding illegal immigration. This paper investigates social media and international news discourses around the Sea-Watch 3 docking, to be regarded as a critical incident capable of catalysing attention and generating a significant media resonance. Results show how both social and traditional media contributed to the proliferation of misogynous attacks against Captain Rackete, at the intersection between right-wing populist discourses of Italian ‘sovranism’ and European anti-immigrationism. By triangulating the role of the media, intersectional hostility and populist ideology, this paper sheds light on how these three factors feed into each other in the discursive construction of the ‘Fortress Europe’ of present times.

Dynamic Positioning Capability Assessment Based on Optimal Thrust Allocation

Abstract The article presents an efficient method of optimal thrust allocation over the actuators in a dynamically positioned ship, according to the DNV-ST-0111 standard, Level 1. The optimisation task is approximated to a convex problem with linear constraints and mathematically formulated as quadratic programming. The case study is being used to illustrate the use of the proposed approach in assessing the DP capability of a rescue ship. The quadratic programming-based approach applied for dynamic positioning capability assessment allows for fast calculations to qualitatively compare different ship designs. In comparison with the DNV tool, it gives 100% successful validation for a ship with azimuth thrusters and a pessimistic solution for a ship equipped with propellers with rudders. Therefore, it can be safely applied at an early design stage.

Cooperative towing for double unmanned surface vehicles connected with a floating rope via vertical formation and adaptive moment control

The surface round-up and towing operations are essential for surface garbage removal, oil spill recovery and shipwrecked ship rescue. All of which are related to the national economy and the people’s livelihood, and it is urgent to improve operation efficiency. This work considers connecting double unmanned surface vehicles (DUSVs) with floating ropes to achieve efficiently autonomous round-up and towing. The core of this research is how to realize autonomous cooperative towing control of DUSV under the interference of floating rope hydrodynamic moment and wind, wave and current. Therefore, a vertical formation control algorithm was proposed to improve the control performance of the DUSV. The virtual leader–follower was treated as the guidance target, and the relative distance between the DUSV and the guidance target should be maintained properly. Next, to reduce the probability of drag separation of DUSV, on the basis of the sensors equipped on the floating rope, an adaptive moment control algorithm was designed via the control of the heading angle error and the adjustment of the moment correction. The results of the simulation and water experiments verified the excellent performance of our algorithms.

Hierarchical Parallel Vision Processor for High-Speed Ship Detection

Ship detection is essential in ship rescue and marine traffic safety. However, high-speed real-time ship detection has become problematic in practical applications. In this brief, we propose a high-performance ship detection system utilizing the co-design of algorithm and hardware. First, the proposed Coarse-to-Fine Classification and Segmentation algorithm contains a two-stage convolutional neural network. It quickly locates the Region of Interest (RoI) and then accurately locates the ship’s position in the RoI without low-parallelism non-maximum suppression (NMS) post-processing. Second, we proposed a Hierarchical Parallel Vision Processor, including a pixel-parallel processing unit, a patch-parallel processing unit, and a global micro-processing unit, ensuring high-speed processing with different parallelism. Finally, we designed a high-speed real-time ship detection system. The experimental results show that our ship detection system based on the frequency of 100Mhz on Arria 10 FPGA can achieve a speed of 4778FPS, which is beneficial in practical applications.

Study of Two Ships Approaching Process and Towing Motion under Wave Action

The rescue of ships in distress at sea relies mainly on rescue vessels, which includes the approaching process and the towing motion of the two ships. Ship rescue can be reduced to a two-ship problem, primarily involving the relative motion between ships during rescue. We established a mathematical model of ship motion based on the viscous fluid N-S equation, and the approaching process of two Wigley ships under waves was simulated in a two-dimensional plane. Then, according to three-dimensional potential flow theory, the coupled motion response model of the ships under six degrees of freedom was constructed, and calculation models of wind, waves, currents and other environmental disturbance factors were established to numerically calculate the towing motion. The results show that the upstream vessel has a lower heave motion amplitude and higher roll motion amplitude during the approaching process; A ratio of 1.5 times the width of the ship is the critical area where the motion of the two ships interacts with each other; For the berthing process, the faster the motion of the active vessel is, the lower the motion amplitude will be for both upstream and downstream vessels. When towing under rough sea conditions, changes in wave height and towing velocity have a large influence on the coupling effect of the towing system. When towing, head-on waves and low sea conditions are preferred, and the velocity should be sufficiently high to reduce the influence of cable self-weight on the towed ship. According to the simulations, the recommended velocity range is 3–5 m/s. Finally, a ship model scaling model was developed based on the similar quasi-Froude number of the ship model test, and the simulation results were verified by conducting parallel and towing tests of the model in a basin with a spherical wave-maker device.

Four Points of View on the Designation of the Navigation Area for Yachts

Usually, the need for research arises when there is a discrepancy between the theoretical and practical data. For example, the RINA (Registro Italiano Navale) Rules describe two navigation areas for yachts: unrestricted navigation and a navigation area with a significant wave height of not more than 4 m. In the GL (Germanischer Lloyd) Rules, it is proposed to assign the maximum wave height that a ship can meet, taking into account its speed and design features. The CCS (China Classification Society) Rules consider five categories of yachts for different navigational conditions. The significant wave height range is from 0.5 m to 6 m, and the distance from the place of refuge is from 5 to 200 nautical miles or more. Directive of the European Parliament and of the Council does not consider the distance from the place of refuge for the ship, and significant wave heights from 0.3 m to 4 m or more are proposed. In practice, the following situations may arise: it is necessary to determine the maximum value of the wave height at which the ship will be able to move against the wave or a possible decrease in the speed of the ship; to determine the height of the wave at which the wetness of the deck will begin; to study the relationship between the allowable values of the design accelerations and technical characteristics of the ship; to determine the distance from the emergency ship to the mooring place of the rescue ship; and calculate the minimum time to render assistance to people. These four situations will be considered in the article by using the energy wave criterion EWC, the recommendations of classification societies, and modeling the behavior of a vessel on a head wave.

Floating sanctuaries: The ethics of search and rescue at sea

AbstractSearch-and-Rescue NGOs in the Mediterranean have been increasingly criminalized. This criminalization has chilled conversation about the ethical dilemmas practitioners face. What, if any, can be the adverse byproducts of rescuing life at sea? In this article, we concentrate on the dilemmas involved in search and rescue (SAR) as rescuers have described them. Our aim is two-fold. The first is to offer a phenomenological account of search-and-rescue dilemmas. The article sheds light on the complexity and nuance of the ethical landscape of maritime rescue, revealing an intricate web of interactions acknowledged by rescuers as posing ethical challenges. The second aim is to offer a conceptual framework for what it is that SAR NGOs are, in fact, doing. We contextualize their actions within the larger terrain of ‘border externalization’, in which states have moved enforcement activities to extraterritorial zones, where human rights law is diluted or inapplicable. We thus argue that the set of norms underlying NGO rescue practices amounts to a strategy of counter-externalization. The ideal here is that a window of opportunity can be created at sea, where human rights or international law protections more broadly apply, but enforcement powers of states are suspended. By utilizing these legal gray zones to the benefit of migrants, rescuers effectively turn extraterritorial zones from spaces of lawlessness into spaces of resistance. The rescue ship thus becomes a ‘floating sanctuary’.

Оптимальное маневрирование судна к аварийному объекту

The article considers the review of planning for the search of a vessel in distress as a tactical method of conducting a search and rescue operation, which is a set of organizational and technical measures that contribute to the detection of the coordinates of the location of the vessel in distress. It has been proved that the effectiveness of the considered planning method depends on the a priori given area, in which the search and detection of the person in distress is conducted. Modern vessels are equipped with such technical means of navigation and communication that clearly solve the problem of uncertainty in the current location of the emergency vessel. The well-known tactical methods of conducting a search and rescue operation can be expanded by organizing the rescue vessel’s getting to a given point in the shortest time interval, which makes it possible to increase the probability of saving the lives. Provided that the technical means of navigation and communication ensure the constant data transfer on the location of the emergency object, there is developed a model of quick approaching the rescue vessel to the emergency object. When drawing up the model of the method, it was assumed that the coordinates of the emergency vessel are constantly broadcast, and the emergency object itself under the influence of external factors (wind, current) drifts rectilinearly and at a constant speed. In the course of evaluating the method effectiveness the performance criterion was used as an efficiency indicator. To determine the minimum time of the ship's leaving the zero point of the Cartesian coordinate system, when the velocity vector of the ship coincides to the positive direction of the abscissa, for the emergency object, it is sufficient to choose the optimal trajectory, according to the Pontryagin maximal principle. The conditions that ensure the application of the Pontryagin principle are met, and therefore the boundary value problem under consideration for a given ship’s dynamics, boundary conditions, and given constraints has the only solution that allows maneuvering of the rescue ship to be carried out in the minimum time (with maximum speed) and with a high probability ratio of life saving equal to 1.

Design and Simulation of Active Hydraulic Interconnected Suspension System for Small Rescue Ship

Design and Simulation of Active Hydraulic Interconnected Suspension System for Small Rescue Ship

Research on the multifunctional oil spill recovery rescue ship

In order to deal with sudden oil spills at sea in a timely and effective manner, the ship mainly uses bubble-type anti-fouling curtains to isolate the pollution, combined with the oil spill recovery device of the bionic jellyfish for oil spill recovery. Traditional oil spill accident handling requires coordination and arrangement of various functional ships to operate separately. The integrated scheme designed in this paper integrates the improved pipe laying device and oil spill recovery device into a unified whole. As the development of marine oil and gas continues to heat up, and the requirements for marine environmental protection in the world continue to increase, there are also higher and higher requirements for oil spill recovery vessels and oil booms. Therefore, a rescue ship that can respond quickly in the event of an oil spill has great prospects.

SDGH-Net: Ship Detection in Optical Remote Sensing Images Based on Gaussian Heatmap Regression

The ship detection task using optical remote sensing images is important for in maritime safety, port management and ship rescue. With the wide application of deep learning to remote sensing, a series of target detection algorithms, such as faster regions with convolution neural network feature (R-CNN) and You Only Look Once (YOLO), have been developed to detect ships in remote sensing images. These detection algorithms use fully connected layer direct regression to obtain coordinate points. Although training and forward speed are fast, they lack spatial generalization ability. To avoid the over-fitting problem that may arise from the fully connected layer, we propose a fully convolutional neural network, SDGH-Net, based on Gaussian heatmap regression. SDGH-Net uses an encoder–decoder structure to obtain the ship area feature map by direct regression. After simple post-processing, the ship polygon annotation can be obtained without non-maximum suppression (NMS) processing. To speed up model training, we added a batch normalization (BN) processing layer. To increase the receptive field while controlling the number of learning parameters, we introduced dilated convolution and added it at different rates to fuse the features of different scales. We tested the performance of our proposed method using a public ship dataset HRSC2016. The experimental results show that this method improves the recall rate of ships, and the F-measure is 85.05%, which surpasses all other methods we used for comparison.

Floating Sanctuaries: The Ethics of Search and Rescue at Sea

Search-and-Rescue NGOs in the Mediterranean have been increasingly criminalized. This criminalization has chilled conversation about the real ethical dilemmas that the practice involves. What, if any, can be the adverse by-products of rescuing life at sea? In this article, we concentrate the dilemmas involved in SAR as seen from the perspective of rescuers. Our aim is twofold. The first is to map the dilemmas from a phenomenological perspective, as they are experienced by rescuers at sea. The paper sheds light on the complexity and nuance of the ethical landscape of maritime rescue, revealing an intricate web of interactions acknowledged by rescuers as posing ethical challenges. The second aim is to offer a conceptual framework for what it is that SAR NGOs are, in fact, doing. We contextualize their actions within the larger terrain of ‘border externalization’, in which states have moved enforcement activities to extraterritorial zones, where human rights law ostensibly does not apply. We thus argue that the set of norms underlying practices developed by SAR NGOs amounts to a strategy of counter-externalization. The idea here is that a window of opportunity can be created at sea, where human rights or international law protections more broadly apply, but enforcement powers of states are suspended. By utilizing these legal grey zones to the benefit of migrants, rescuers effectively turn extraterritorial zones from spaces of lawlessness into spaces of resistance. The rescue ship thus becomes a ‘floating sanctuary’.

Residents working with M\xe9decins Sans Fronti\xe8res: training and pilot evaluation

BackgroundWell-prepared humanitarian workers are now more necessary than ever. Essential to the preparation process are: clearly defined learning objectives, curricula tailored to the nuances of humanitarian settings, simulation-based training, and evaluation. This manuscript describes a training program designed to prepare medical residents for their first field deployment with Médecins Sans Frontières and presents the results of a pilot assessment of its effectiveness.MethodsThe training was jointly developed by the Research Center in Emergency and Disaster Medicine- CRIMEDIM of the Università del Piemonte Orientale, Novara, Italy, and the humanitarian aid organization Médecins Sans Frontières- Italy (MSF-Italy); the following topics were covered: disaster medicine, public health, safety and security, infectious diseases, psychological support, communication, humanitarian law, leadership, and job-specific skills. It used a blended-learning approach consisting of a 3-month distance learning module; 1-week instructor-led coaching; and a field placement with MSF. We assessed its effectiveness using the first three levels of Kirkpatrick’s training evaluation model.ResultsEight residents took part in the evaluation. Four were residents in emergency medicine, 3 in anesthesia, and 1 in pediatrics; 3 of them were female and the median age was 31 years. Two residents were deployed in Pakistan, 1 in Afghanistan, 1 in the Democratic Republic of Congo, 1 in Iraq, 2 in Haiti and 1 on board of the MSF Mediterranean search & rescue ship. Mean deployment time was 3 months. The average median score for the overall course was 5 (excellent). There was a significant improvement in post-test multiple choice scores (p = 0.001) and in residents’ overall performance scores (P = 0.000001).ConclusionResidents were highly satisfied with the training program and their knowledge and skills improved as a result of participation.Trial registrationThis study was approved by the Institutional Ethics Committee (date 24-02-2016, study code UPO.2015.4.10).

Performance Evaluation of Maritime Search and Rescue Missions Using Automatic Identification System Data

In maritime search and rescue (SAR), commanders need to understand the task execution efficiency of each SAR unit in real time to improve the overall efficiency of SAR efforts. This study proposes a method to evaluate the progress of maritime SAR missions using automatic identification system (AIS) data. First, the positioning accuracy of the AIS data was improved according to the relationship between position, speed, and course. Second, the historical track of the SAR ship was used to generate the SAR completion area based on a line buffer algorithm. The SAR completion area and SAR mission area were then superimposed to determine the overall progress of the SAR mission. The proposed method has been deployed within the SAR software on-board Haixun01 (China's largest and most advanced large-scale cruise rescue ship) since 2017 and has played an important role in devising SAR strategies and tracking mission progress, during several SAR actions.