The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform

Dracos Vassalos - One of the best experts on this subject based on the ideXlab platform.

  • Passenger Ship evacuation design and verification
    International Conference on Virtual Augmented and Mixed Reality, 2014
    Co-Authors: Luis Guari, Yasmine Hifi, Dracos Vassalos
    Abstract:

    This paper introduces the concept of escape and evacuation from Passenger Ships from a perspective of Ship design and risk management. As part of that process, the use of computer simulation tools for analysing the evacuation performance of Ships carrying large numbers of persons on board is becoming more relevant and useful. The objective of this paper is to present the pedestrian dynamics simulation tool EVI, developed to undertake advanced escape and evacuation analysis in the design verification of cruise vessels, Passenger ferries and large offshore construction vessels, among others.

  • damage stability and survivability nailing Passenger Ship safety problems
    Ships and Offshore Structures, 2014
    Co-Authors: Dracos Vassalos
    Abstract:

    With artefacts on human endeavours at sea dating as far back as 6500 BC, it is mind boggling to think that it was not until 250 BC when the first recorded steps to establish the foundation of naval architecture, floatability and stability, were made by Archimedes. It is even more astonishing that practical pertinence and function of these two very basic principles remained dormant for nearly two millennia after this, before the first attempts to convey the meaning of stability to men of practice took place in the eighteenth century by Hoste and Bouguer. Pertinent regulations, especially after accidents involving water ingress and flooding (through subdivision and damage stability), were introduced even much later. Notably, the first Merchant Shipping Act of 1854 addressed subdivision and led eventually and after heavy loss of life to the adoption of the first internationally agreed system of subdivision in SOLAS 1929 (Safety of Life at Sea), while the first specific criterion on residual static stability ...

  • Passenger Ship safety containing the risk
    Marine technology, 2006
    Co-Authors: Dracos Vassalos
    Abstract:

    This paper presents a review of current risk-based design as applied to Passenger Ship safety and highlights future developments. Emphasis Is placed on demonstrating the considerable potential offered to the marine industry by embracing innovation, in terms of routine utilization in the Ship design process of scientific and technological breakthroughs, to contain risk. Language: en

  • Passenger Ship safety science paving the way
    Marine Systems & Ocean Technology, 2006
    Co-Authors: Dracos Vassalos, Andrzej Jasionowski, Luis Guari
    Abstract:

    The prevailing regulatory framework addressing Ship safety originates in some distant past and carries a heavy “baggage” of experiential determinism and rules of thumb; all throwing a smoke screen onto science and quenching most attempts to dealing with safety in a scientific, all embracing and systematic approach. Goal-Based Standards are meant to provide anew impetus to achieve this but experience so far suggests if anything even more determinism and even less science in the strife to face uncertainty and complexity with only “crumbs” of understanding of the real issues at hand. There is only one real exception, giving science the opportunity and all of us hope that scientific approaches to addressing safety will at long last be called upon to pave and lead the way: [Large] Passenger Ship Safety. Nothing is meant to be preconceived here; safety can have a field day before it is cut down to face reality and cost. Goal-Based Approaches, Casualty Threshold, Safe Haven, Safe Area, “Zero” Tolerance in human life loss, De-risked Ships; all goes and is being seriously discussed at IMO. This paper presents a critique of recent developments at IMO, in particular the new probabilistic rules of damage stability calculations, in an attempt to demonstrate the need to use knowledge in all its forms to make a difference in safety improvement before proceeding to suggesting a workable approach to address one exciting development in the regulatory front: Casualty Threshold. Emphasis is placed on explaining the framework that could embrace and support such development and on the pre-requisite scientific knowledge to realise it.

Ioanna Koromila - One of the best experts on this subject based on the ideXlab platform.

  • a risk model of Passenger Ship fire safety and its application
    Reliability Engineering & System Safety, 2020
    Co-Authors: Kostas J Spyrou, Ioanna Koromila
    Abstract:

    Abstract A risk model for assessing a Passenger Ship's fire safety at the design stage is proposed. Current maritime legislation requires, in principle, compliance with prescriptive regulations of fire prevention, protection and extinction. In a forward step, the International Maritime Organization (IMO) permitted acceptance of fire-safety-equivalent designs on the basis of performance-based assessment procedures. However, the inherent randomness of onboard fire events has not yet been systematically accounted. In this respect, procedures currently applied for fire safety evaluation during Ship design, lag behind those applied for the avoidance of Ship capsize due to watertight compartments’ flooding, where a probabilistic approach has been in place since long ago. The current work is intended to enhance the probabilistic character of performance-based Ship fire assessments; and to establish a consistent risk calculation framework which could also serve in the future as the backbone model of a more integrated approach to Ship risk calculation. The core of the proposed model is a risk function combining the probability of ignition, the reliability of the installed suppression systems, and the prediction of the loss given a fire's growth. Design details, such as the space layout and the interior design materials, are fully taken into account. The estimation of the loss is realized by high fidelity simulations. The loss appears in the form of a distribution of fatalities. Several practical risk indices are extracted from the risk function, reflecting potential designer preferences. For demonstrating the practicality of the proposed risk model, a part of a cruise Ship's fire zone, accommodating public spaces, is considered. The fire safety performance of the design is evaluated by using the extracted risk indices whose consistency in reflecting the safety level are discussed.

Kostas J Spyrou - One of the best experts on this subject based on the ideXlab platform.

  • a risk model of Passenger Ship fire safety and its application
    Reliability Engineering & System Safety, 2020
    Co-Authors: Kostas J Spyrou, Ioanna Koromila
    Abstract:

    Abstract A risk model for assessing a Passenger Ship's fire safety at the design stage is proposed. Current maritime legislation requires, in principle, compliance with prescriptive regulations of fire prevention, protection and extinction. In a forward step, the International Maritime Organization (IMO) permitted acceptance of fire-safety-equivalent designs on the basis of performance-based assessment procedures. However, the inherent randomness of onboard fire events has not yet been systematically accounted. In this respect, procedures currently applied for fire safety evaluation during Ship design, lag behind those applied for the avoidance of Ship capsize due to watertight compartments’ flooding, where a probabilistic approach has been in place since long ago. The current work is intended to enhance the probabilistic character of performance-based Ship fire assessments; and to establish a consistent risk calculation framework which could also serve in the future as the backbone model of a more integrated approach to Ship risk calculation. The core of the proposed model is a risk function combining the probability of ignition, the reliability of the installed suppression systems, and the prediction of the loss given a fire's growth. Design details, such as the space layout and the interior design materials, are fully taken into account. The estimation of the loss is realized by high fidelity simulations. The loss appears in the form of a distribution of fatalities. Several practical risk indices are extracted from the risk function, reflecting potential designer preferences. For demonstrating the practicality of the proposed risk model, a part of a cruise Ship's fire zone, accommodating public spaces, is considered. The fire safety performance of the design is evaluated by using the extracted risk indices whose consistency in reflecting the safety level are discussed.

Kyuyeul Lee - One of the best experts on this subject based on the ideXlab platform.

  • Passenger Ship evacuation simulation considering external forces due to the inclination of damaged Ship
    Journal of The Society of Naval Architects of Korea, 2013
    Co-Authors: Kyuyeul Lee, Myungil Roh
    Abstract:

    3 3 This paper presents a simulation for Passenger Ship evacuation considering the inclination of a Ship. In order to describe a Passenger's behavior in an evacuation situation, a Passenger is modeled as a rigid body which translates in the horizontal plane and rotates along the vertical axis. The position and rotation angle of a Passenger are calculated by solving the dynamic equations of motions at each time step. To calculate inclined angle of damaged Ship, static equilibrium equations of damaged Ship are derived using "added weight method". Using these equations, physical external forces due to the inclination of a Ship act on the body of each Passenger. The crowd behavior of the Passenger is considered as the flock behavior, a form of collective behavior of a large number of interacting Passengers with a common group objective. Passengers can also avoid an obstacle due to penalty forces acting on their body. With the Passenger model and forces acting on its body, the test problems in International Maritime Organization, Maritime Safety Committee/Circulation 1238(IMO MSC/Circ.1238) are implemented and the effects of Ship's inclination on the evacuation time are confirmed.

  • cell based evacuation simulation considering human behavior in a Passenger Ship
    Ocean Engineering, 2012
    Co-Authors: Myungil Roh, Kyuyeul Lee
    Abstract:

    Abstract Advanced evacuation analysis of Passenger Ships is a stochastic method in which the total evacuation time is calculated via computer-based simulations, by considering each Passenger's characteristics (e.g., age, gender, etc.) and the detailed layout of the Ship. This study presents simulations of advanced evacuation analysis using a cell-based simulation model for human behavior in a Passenger Ship. The cell-based simulation model divides the space in a uniform grid called cell. Each Passenger is located in a cell and moves to another cell according to a set of local rules that are assumed to be associated with the individual, crowd, and counterflow-avoiding behaviors of the Passengers. Individual behavior is described with the basic walking direction that a Passenger will take during the evacuation. The change in the direction and speed of a Passenger based on his/her interaction with the other Passengers is expressed via the crowd behavior, which has three basic rules: separation, alignment, and cohesion. The Passenger's behavior to avoid other Passengers moving in the opposite direction is referred to as “counterflow-avoiding behavior” because such counterflow is included in the evacuation scenario. These behavior patterns are implemented as the local rules and are assigned to each cell. To verify the usefulness of the proposed simulation model, 11 tests specified in International Maritime Organization Maritime Safety Committee/Circulation 1238 (IMO/MSC Circ. 1238) were conducted, and it was confirmed that all the requirements of such tests had been met.

  • evacuation analysis for a Passenger Ship using a cellular automata model with group behavior
    Journal of the Korea Society for Simulation, 2011
    Co-Authors: Juhwa Cha, Kyuyeul Lee
    Abstract:

    ABSTRACTThis paper presents simulations of advance evacuation analysis using a cellular automata model for Passenger behavior in an emergency of Passenger Ship. The proposed cellular automata model divides the space in a uniform grid called “cell.” Each Passenger is located in a cell and moves to another cell according to a set of local rules assumed to be associated with the individual and crowd behaviors of the Passengers. To verify the usefulness of the proposed cellular automata model, 11 tests, all of which are specified in International Maritime Organization Maritime Safety Committee/ Circulation 1238 (IMO MSC/Circ. 1238), were implemented, and it was confirmed that all the requirements of these tests had been met. Key words : Advanced Evacuation Analysis, Passenger Ship, Cellular Automata, Crowd Behavior요 약본 논문에서는 여객선의 비상 상황에서의 승객 탈출 시 승객의 집단 행동을 고려한 cellular automata 모델을 제안하였다. 승객이 이동 가능한 영역을 규칙적인 격자 형태의 cell들로 표현하고, 한 명의 승객이 일반적으로 차지하는 공간의 크기를 cell의 크기로 정의한다. 각 cell은 이웃 cell들의 상태를 고려하여 정해진 규칙에 따라 승객이 이동함으로써 매 단위 시간마다 cell의 상태가 업데이트 된다 . 규칙은 탈출구로의 이동 규칙과 집단 행동 규칙의 두 가지로 구성되어 있다 . 첫째, 탈출구로의 이동 규칙을 정의하기 위해 각 cell에는 탈출구로의 최단 거리가 저장되어 있고 , 인접한 8개의 이웃 cell에 저장된 거리 값들을 비교하여 거리 값이 작아지는 방향으로 승객이 이동한다 . 둘째, 집단 행동 규칙은 응집 (cohesion), 분리(separation), 정렬(alignment) 행동 규칙으로 구성되어 있다 . 이러한 승객의 집단 행동을 규칙화 한 cellular automata 모델을 사용하여 International Maritime Organization, Maritime Safety Committee / Circulation 1238(IMO MSC/Circ. 1238) 기반의 여객선 승객 탈출 분석을 수행하여 승객의 이동 경로 및 탈출 시간을 계산하였다 .주요어 : 승객 탈출 분석, 여객선, Cellular Automata, 집단 행동

  • advanced evacuation analysis for Passenger Ship using penalty walking velocity algorithm for obstacle avoid
    Journal of the Korea Society for Simulation, 2010
    Co-Authors: Kwangphil Park, Yoonok Cho, Kyuyeul Lee
    Abstract:

    ABSTRACTIn this paper, advanced evacuation analysis simulation on a Passenger Ship is performed. Velocity based model has been implemented and used to calculate the movement of the individual Passengers under the evacuation situation. The age and gender of each Passenger are considered as the factors of walking speed. Flocking algorithm is applied for the Passenger’s group behavior. Penalty walking velocity is introduced to avoid collision between the Passengers and obstacles, and to prevent the position overlap among Passengers. Application of flocking algorithm and penalty walking velocity to evacuation simulation is verified through implementation of the 11 test problems in IMO (Interna-tional Maritime Organization) MSC (Maritime Safety Committee) Circulation 1238. Key words : Evacuation analysis, Velocity based model, Penalty walking velocity, Flocking algorithm요 약본 논문에서는 여객선의 승객 비상 탈출 시뮬레이션을 구현하였다 . 승객의 행동에 미치는 요인 중 연령 , 성별을 고려하여 승객 개인의 보행 속도에 반영하는 속도 기반 모델을 사용하였다 . 승객들의 집단 이동을 구현하기 위해 플로킹 알고리즘을 적용하였다. 장애물과의 충돌 회피 및 승객 간의 위치가 겹치는 현상을 방지하기 위해 페널티 보행 속도를 도입하였다 . 이 알고리즘을 이용하여 여객선의 승객 탈출 규정인 IMO (International Maritime Organization) MSC (Maritime Safety Committee) Circ.1238 에서 정의한 11가지 시험 문제에 적용하였다 . 시험 문제를 통해 승객의 위치가 겹치는 현상이 없이 시뮬레이션 되는 것을 확인하였다 .주요어 : 탈출 분석, 속도 기반 모델, 페널티 보행 속도, 플로킹 알고리즘

Yoshiho Ikeda - One of the best experts on this subject based on the ideXlab platform.

  • experimental and numerical studies on roll motion of a damaged large Passenger Ship in intermediate stages of flooding
    2011
    Co-Authors: Yoshiho Ikeda, Toru Katayama, Shigesuke Ishida, Yuji Takeuchi
    Abstract:

    Measurements of roll motion of a two-dimensional scale model of a damaged large Passenger Ship are carried out during flooding process. The experimental results demonstrate that large and slow roll motion sometimes appears in the intermediate stages of flooding. The appearance of the large roll motion significantly depends on location and size of damage opening. It is also confirmed that the simulated results are in fairly good agreement with experimental ones.

  • parametric roll resonance of a large Passenger Ship in dead Ship condition in all heading angles
    Fluid Mechanics and its Applications, 2011
    Co-Authors: Abdul Munif, Yoshiho Ikeda, Tomo Fujiwara, Toru Katayama
    Abstract:

    Although it has been widely believed that a Ship in dead Ship condition has the largest roll motion at resonance condition, the authors found that, because of parametric roll resonance, a kind of Ships has significant heavy rolling in beam waves with slightly smaller period of the half value of its natural roll period if the roll damping is small. In the present paper, model experiments to measure Ship motions of a large Passenger Ship in waves with various heading angle are carried out to confirm the region of heading angles where large parametric rolling appears. The results demonstrate that parametric rolling appears at wide region of heading angles and disappears in certain heading angles.

  • Large parametric rolling of a large Passenger Ship in beam seas and the role of bilge keel in its restraint
    Marine Systems & Ocean Technology, 2006
    Co-Authors: Yoshiho Ikeda, Abdul Munif, Toru Katayama, Tomo Fujiwara
    Abstract:

    Model experiments of a scale model of a large Passenger Ship without bilge keels in beam seas demonstrate that parametric roll resonance with roll amplitude can reach more than 25 degrees occurs in the range of short waves. It is identified that the change of wave height affects the change of metacentric height in waves so that it affects the occurrence of the parametric rolling in beam seas. It is experimentally confirmed that the designed bilge keels for the Ship can restrain such parametric rolling. Moreover, the experiments with various sizes of bilge keels show that they can affect the occurrence of parametric rolling in beam seas.

  • cruising performance of a large Passenger Ship in heavy sea
    The Sixteenth International Offshore and Polar Engineering Conference, 2006
    Co-Authors: Toshifumi Fujiwara, Michio Ueno, Yoshiho Ikeda
    Abstract:

    The authors proposed a new estimation method of wind forces and moments acting on Ships based on a physical-component-model of the wind loads. In this paper, using the wind loads estimation method, steady cruising performances of a large Passenger Ship are estimated in heavy sea in order to assess the strong wind and waves effects. Some important characteristics of the resistance increase in steady cruising condition in heavy sea for the large Passenger Ship are clearly revealed in the calculation.