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On the Structural Behaviour to Penetration of Striking Bow under Collision Incidents between Two Ships

INTERNATIONAL JOURNAL OF AUTOMOTIVE AND MECHANICAL ENGINEERING 2019年第4期16卷 7480-7497页

作者： Prabowo, A. R. Nubli, H. Sohn, J. M. Univ Sebelas Maret Dept Mech Engn Surakarta 57126 Central Java Indonesia Pukyong Natl Univ Interdisciplinary Program Marine Convergence Desi Busan 48513 South Korea Pukyong Natl Univ Dept Naval Architecture & Marine Syst Engn Busan 48513 South Korea

This work addressed the evaluation of collision angle and indenter on the behaviour of target object. A series of collision scenarios based on the mentioned parameters were calculated using finite element method. In the analysis process, several striking ships of different sizes relative to the struck ship are deployed as the collision angles ranging from 0 degrees to 180 degrees are taken into consideration. The results relative to the angles show that the perpendicular collision or a collision angle of 90 degrees produces the lowest level of the internal energy in the side collision category by comparison with oblique collisions in the range of collision angles from 30 degrees to 150 degrees. The internal energy is found to be satisfactory when it is compared with the extent of the damage on the outer shell, which is also matched with the predicted energy behaviour from energy formulae.

关键词： ship collision collision angle finite element analysis structural behaviour extent of damage

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DispSegNet: Leveraging Semantics for End-to-End Learning of Disparity Estimation From Stereo Imagery

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IEEE ROBOTICS AND AUTOMATION LETTERS 2019年第2期4卷 1162-1169页

作者： Zhang, Junming Skinner, Katherine A. Vasudevan, Ram Johnson-Roberson, Matthew Univ Michigan Dept Elect Engn & Comp Sci Ann Arbor MI 48109 USA Univ Michigan Robot Program Ann Arbor MI 48109 USA Univ Michigan Dept Mech Engn Ann Arbor MI 48109 USA Univ Michigan Dept Naval Architecture & Marine Engn Ann Arbor MI 48109 USA

Recentwork has shown that convolutional neural networks (CNNs) can be applied successfully in disparity estimation, but these methods still suffer from errors in regions of low texture, occlusions, and reflections. Concurrently, deep learning for semantic segmentation has shown great progress in recent years. In this letter, we design a CNN architecture that combines these two tasks to improve the quality and accuracy of disparity estimation with the help of semantic segmentation. Specifically, we propose a network structure in which these two tasks are highly coupled. One key novelty of this approach is the two-stage refinement process. Initial disparity estimates are refined with an embedding learned from the semantic segmentation branch of the network. The proposed model is trained using an unsupervised approach, in which images from one half of the stereo pair are warped and compared against images from the other camera. Another key advantage of the proposed approach is that a single network is capable of outputting disparity estimates and semantic labels. These outputs are of great use in autonomous vehicle operation;with real-time constraints being key, such performance improvements increase the viability of driving applications. Experiments on KITTI and Cityscapes datasets show that our model can achieve state-of-the-art results and that leveraging embedding learned from semantic segmentation improves the performance of disparity estimation.

关键词： Computer vision for transportation deep learning in robotics and automation

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Integrating berth allocation decisions in a fleet composition and periodic routing problem of platform supply vessels

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EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 2019年第1期275卷 334-346页

作者： Cruz, Roberto Mendes, Andre Bergsten Bahiense, Laura Wu, Yue Univ Sao Paulo Dept Naval Architecture & Ocean Engn Sao Paulo Brazil Univ Fed Rio de Janeiro Syst Engn & Comp Sci Program Transportat Engn Program Alberto Luiz Coimbra InstGrad Sch & Res Engn Rio De Janeiro Brazil Petrobras R&D Ctr CENPES Rio De Janeiro Brazil Univ Southampton Southampton Business Sch Southampton Hants England

The aim of this work is to present mathematical models and a heuristic solution strategy to solve the heterogeneous fleet-sizing problem of platform supply vessels (PSVs) that support the offshore oil and gas exploration and production (E&P) activities. The problem considered in this research takes into account a novel characteristic related to the berth allocation problem of the supply base, which must be considered together with the decisions of selecting the departure days and the routes. The adopted solution strategy consists of sequentially solving models that capture different aspects of the problem, by starting with models that are simpler to solve. The solution found in one step provides a lower bound to the next step. This procedure was devised in order to reduce the search space and to speed up convergence. The proposed solution strategy was applied to real instances in Brazil, which has up to 79 offshore units grouped into clusters, with fair/acceptable results. The procedure allowed for assessing the impact of the number of berths on the fleet composition. (C) 2018 Elsevier B.V. All rights reserved.

关键词： OR in maritime industry Heterogeneous fleet sizing Berthallocation Periodic routing Offshore supply vessels

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Energy Dissipation of Ship Structures subjected to Impact Loading: A Study Case in Side Collision

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Procedia Structural Integrity 2020年 27卷 171-178页

作者： Aditya Rio Prabowo Haris Nubli Jung Min Sohn Department of Mechanical Engineering Universitas Sebelas Maret Surakarta 57126 Indonesia Interdisciplinary Program of Marine Convergence Design Pukyong National University Busan 48513 South Korea Department of Naval Architecture and Marine Systems Engineering Pukyong National University Busan 48513 South Korea

The main goal of the present paper is to study the energy dissipation characteristic as the influence of parameters in the event of ship collisions. The review is conducted on accident case between Roll on-Roll off (Ro-Ro) Marisa Nusantara with Reefer Qi Hang at Sunda Strait, Indonesia May 3rd, 2014, as reference. It was later modeled and analyzed by nonlinear simulations finite element (FE) method was presented to be used as a reference to get the verified model. This collaboration study is considered as a good reference because it used real accident damage to compare the numerical results. The result in collision energy from the virtual simulation was later verified with the calculation result of the empirical formula. In the extended study, the collision region and material model are selected as influenced parameters to design collision scenarios. The characteristic of collision energy from these scenarios will be discussed. In the same section, the damage pattern is observed and reviewed to find the relation between several parameters to calculation results. It was shown that the influence of region and location of target points contributed significantly to energy dissipation. In contrast, the key finding in material properties is that when Young’s modulus between materials was the same and the difference of yield strength of materials was not significant, then other material properties contributed to the result.

关键词： Accidental loads ship collision Ro-Ro vessel double-hull structures crashworthiness energy dissipation

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The role of social influence in blockchain adoption: The Brazilian supply chain case

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IFAC-PapersOnLine 2019年第13期52卷 1715-1720页

作者： Wamba, Samuel Fosso Queiroz, Maciel M. Toulouse Business School - TBS Information Operations and Management Sciences ToulouseCO31068 France Paulista University - UNIP Postgraduate Program in Administration São PauloCO04026-002 Brazil University of São Paulo Naval Architecture and Ocean Engineering São PauloCO05508-030 Brazil

The aim of this study is to understand the blockchain adoption behaviour in Brazilian supply chains. Specifically, the study aims to unlock the potential of social influence; taking into consideration workers from the Brazilian supply chains. We proposed a model using constructs from a unified theory of acceptance and the use of technology (UTAUT). The models were analysed using partial least squares structural equation modelling (PLS-SEM) and the findings indicated the power of social influence in predicting other UTAUT constructs. In addition, this study shows the mediation effect of effort expectancy and the facilitating conditions in the relationship between social influence and the behavioural intention to adopt blockchain. Finally, our findings bring essential theoretical and managerial implications. © 2019, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Economic and social effects

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On the nuclear safety improvement by post-inerting small modular reactor with stainless steel cladding

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ANNALS OF NUCLEAR ENERGY 2020年 149卷 107775-107775页

作者： Avelar, Alan Matias Mourao, Marcelo Breda Maturana, Marcos Giovedi, Claudia Abe, Alfredo Yuuitiro Pedrassani, Rafaela Su, Jian Univ Sao Paulo Polytech Sch Dept Met & Mat Engn Prof Mello Moraes Cidade Univ 2463 Sao Paulo SP Brazil Univ Sao Paulo Polytech Sch Dept Naval Architecture & Ocean Engn Anal Evaluat & Risk Management Lab Prof Mello Moraes Cidade Univ 2231 Sao Paulo SP Brazil Univ Sao Paulo Nucl & Energy Res Inst Prof Lineu Prestes Cidade Univ 2242 Sao Paulo SP Brazil Univ Fed Rio de Janeiro COPPE Nucl Engn Program CP 68509Cidade Univ Rio De Janeiro Brazil

After Fukushima Daiichi accident, the replacement of zirconium-based fuel cladding in Light Water Reactors (LWR) became one of the main challenges of the nuclear industry. Austenitic steel-clad presents some safety advantages comparing to zirconium alloys, noticeably, higher activation energy and lower enthalpy of metal-water reaction. Thus, it produces a slower hydrogen release into the containment following a postulated accident. In this study, a Loss-of-Coolant Accident (LOCA) aggravated by the complete failure of the Emergency Core Cooling System (ECCS) is analyzed for a Small Modular Reactor (SMR). Post-accident injection of inert gas into the containment is used as one of the hydrogen control systems, to enhance safety margins during Severe Accidents (SA). The inertization system is successful in complementing Passive Autocatalytic Recombiners (PAR) to perform combustible gas control. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Stainless steel Hydrogen Post-inerting Small modular reactor Containment

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Numerical Study of Fillet Surface Effect on the Ducted Performance Using OpenFOAM 9

Numerical Study of Fillet Surface Effect on the Ducted Perfo...

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9th Asia Conference on Mechanical and Aerospace Engineering (ACMAE)

作者： Bahatmaka, Aldias Kim, Dong Joon Pranggono, Hadi Pukyong Natl Univ Interdisciplinary Program Marine Convergence Desi Busan 48513 South Korea Pukyong Natl Univ Naval Architecture & Marine Syst Engn Dept Busan 48513 South Korea Pekalongan Univ Aquaculture Dept Pekalongan 51115 Indonesia

In the present study, the effect of fillet surface on the performance of the ducted propeller using Reynolds-Average Navier Stokes (RANS) method is applied. The numerical simulations compare the propeller model with fillet on the surface and without fillet. OpenFOAM is used to simulate the performances and solve the problems in the open water propeller simulation. MRF approach is applied for this simulation. Kaplan model with the 19A nozzle is investigated by comparing the results with experimental data. The effect of fillet surface on the ducted propeller are presented and discussed in this study.

关键词： Navier Stokes equations

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Ultimate Strength Assessment of Steel-Welded Hemispheres under External Hydrostatic Pressure

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Journal of Marine Science and Application 2020年第4期19卷 615-633页

作者： Sang-Rai Cho Teguh Muttaqie Seung Hyun Lee Jaewoo Paek Jung Min Sohn Ulsan Lab Inc.UlsanSouth Korea School of Naval Architecture and Ocean Engineering University of UlsanUlsanSouth Korea Department of Naval Architecture and Marine Systems Engineering Pukyong National UniversityBusanSouth Korea Agency for the Assessment and Application of Technology Center of Technology for Defense and Security Industries-BPPTJakartaIndonesia Hyundai Mipo Dockyard UlsanSouth Korea Hyundai Heavy Industries UlsanSouth Korea Interdisciplinary Program of Marine Convergence Design Pukyong National UniversityBusanSouth Korea

This paper focusses on steel-welded hemispherical shells subjected to external hydrostatic *** experimental and numerical investigations were performed to study their failure *** model was fabricated from mild steel and made through press forming and *** therefore considered the effect of initial shape imperfection,variation of thickness and residual stress obtained from the actual *** hemisphere models designed with R/t from 50 to 130 were tested until *** to the test,the actual geometric imperfection and shell thickness were carefully *** comparisons of available design codes(PD 5500,ABS,DNV-GL)in calculating the collapse pressure were also highlighted against the available published test data on steel-welded ***,the nonlinear FE simulations were also conducted to substantiate the ultimate load capacity and plastic deformation of the models that were *** dependence of the level of sphericity,varying thickness and residual welding stresses were also numerically considered in the benchmark *** structure behaviour from the experiments was used to verify the numerical *** this work,both collapse pressure and failure mode in the numerical model were consistent with the experimental model.

关键词： Steel-welded hemisphere Collapse pressure Experiment Nonlinear FEA Ultimate strength formulation

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Nonlinear analysis of inter-island RoRo under impact: effects of selected collision's parameters on the crashworthy double-side structures

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JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING 2018年第5期40卷 1-21页

作者： Prabowo, Aditya Rio Muttaqie, Teguh Sohn, Jung Min Bae, Dong Myung Pukyong Natl Univ Interdisciplinary Program Marine Convergence Desi Busan South Korea Univ Diponegoro Dept Naval Architecture Semarang Indonesia Agcy Assessment & Applicat Technol Cent Jakarta Indonesia Pukyong Natl Univ Dept Naval Architecture & Marine Syst Engn Busan South Korea

The purpose of this paper is to study the effect of selected parameters in ship collision and extend it to assessment of structural crashworthiness on the double-side structure (DSS). A brief concept and implementation of the ship-ship interaction is presented in early discussion, which is followed by fundamental factors in numerical calculation. Initial analysis is addressed to quantify influence of several element formulations types on damage extent and simulation time. According to comparison with certain RoRo collision incident data, the fully integrated version of the Belytschko-Tsay emerges as the most similar in terms of the damage criterion of analysis. Even though ordinary type of the Belytschko-Tsay produces faster time processing, fully integrated version is still chosen as it can prevent undesired phenomena during nonlinear finite element analysis. The next analysis aims to conduct crashworthiness assessment on several regions of the target ship. Collision location and attacking velocity are determined as representative of the external dynamic parameters, while material grade is considered as the internal parameter. Assessment results of the DSS are presented in forms of the statistical calculation to obtain variance percentage, and failure sequence to understand crushing process during side collision. Result tendency indicates that the velocity is nominated as the most influencing parameters to the crashworthiness criteria of the target ship.

关键词： Ship-ship collision scenario Nonlinear FE analysis Shell element formulation Double-side structure (DSS) Bow-hull interaction Material characterization Crashworthiness criteria

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Solar Energy for a Traditional Coastal Fishing Platform

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Journal of Marine Science and Application 2019年第3期18卷 366-371页

作者： Sunaryo Aldy Syahrihaddin Pradhana Shadu Imfianto Indonesian Maritime Center Universitas IndonesiaDepok 16424Indonesia Naval Architecture and Marine Engineering Study Program Universitas IndonesiaDepok 16424Indonesia

In order to introduce clean environment and sustainable energy to traditional coastal fishing community, the objective of this study is to encourage the Indonesian traditional coastal fishing community to use green and renewable energy in their fishing activities. Introducing solar power as the main source of energy for fish-attracting lights and boat propulsion can reduce the use of fossil fuels, and sustain clean and healthy environment. As the world’s largest archipelago, Indonesia accounts for a high percentage of traditional fishing communities spread out along its islands. This fishing communities use various traditional fishing boats, and platforms. The fishing platforms are usually made of bamboo and placed on top of supporting structures on the seabed. Diesel electric generators are used to obtain electricity needed for lighting to attract the fish at night, and as the source of power for lifting the fishing net. The structure and fuel used are neither environmentally friendly nor clean;thus, an innovation is introduced. Traditional fishing practices using a fishing platform were studied, including the common size of the platform and the power needed for the fishing light. Based on the gathered information, this study proposes a catamaran vessel with a special top structure designed for fish lifting outfitting, and equipped with photovoltaic solar cells as the energy source for the fishing lights and vessel propulsion. Through this innovative break through, the vessel can be moved to the shore and will not be a threat to ship navigation and the environment. Furthemore, powered by clean and sustainable energy, the vessel can be directed to the best fishing ground.

关键词： Catamaran Fishing lights Fishing platform Lifting net Photovoltaic panel Solar energy

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