Stochastic Modeling of Forces on Jacket-Type Offshore Structures Colonized by Marine Growth

The present paper deals with the stochastic modeling of bio-colonization for the computation of stochastic hydrodynamic loading on jacket-type offshore structures. It relies on a multidisciplinary study gathering biological and physical research fields that accounts of uncertainties at all the levels. Indeed, bio-colonization of offshore structures is a complex phenomenon with two major but distinct domains (i) marine biology whose processes are modeled with biomathematics methods and (ii) hydrodynamic processes. This paper aims to connect these two domains. It proposes a stochastic model for the marine organism’s growth and then continues with transfers for assessment of drag coefficient and forces probability density functions that accounts for marine growth evolution. A case study relies on the characteristics (growth and shape) of the blue mussel (Mytilus edulis) in northeastern Atlantic.

Download Full-text

Stochastic Modeling of Forces on Jacket-Type Offshore Structures Colonized by Marine Growth

Journal of Marine Science and Engineering ◽

10.3390/jmse7050158 ◽

2019 ◽

Vol 7 (5) ◽

pp. 158 ◽

Cited By ~ 2

Author(s):

Hamed Ameryoun ◽

Franck Schoefs ◽

Laurent Barillé ◽

Yoann Thomas

Keyword(s):

Stochastic Modeling ◽

Marine Biology ◽

Blue Mussel ◽

Offshore Structures ◽

Research Fields ◽

Multidisciplinary Study ◽

Hydrodynamic Processes ◽

Growth Evolution ◽

Northeastern Atlantic

The present paper deals with the stochastic modeling of bio-colonization for the computation of stochastic hydrodynamic loading on jacket-type offshore structures. It relies on a multidisciplinary study gathering biological and physical research fields that accounts for uncertainties at all the levels. Indeed, bio-colonization of offshore structures is a complex phenomenon with two major but distinct domains: (i) marine biology, whose processes are modeled with biomathematics methods, and (ii) hydrodynamic processes. This paper aims to connect these two domains. It proposes a stochastic model for the marine organism’s growth and then continues with transfers for the assessment of drag coefficient and forces probability density functions that account for marine growth evolution. A case study relies on the characteristics (growth and shape) of the blue mussel (Mytilus edulis) in the northeastern Atlantic.

Download Full-text

Correction: The Role of Hydrodynamic Processes on Anchovy Eggs and Larvae Distribution in the Sicily Channel (Mediterranean Sea): A Case Study for the 2004 Data Set

PLoS ONE ◽

10.1371/journal.pone.0129990 ◽

2015 ◽

Vol 10 (6) ◽

pp. e0129990

Author(s):

Keyword(s):

Mediterranean Sea ◽

Data Set ◽

Hydrodynamic Processes ◽

Sicily Channel ◽

Eggs And Larvae

Download Full-text

Productivity analysis of education and research fields in universities of medical sciences: a case study of Iran

International Journal of Productivity and Quality Management ◽

10.1504/ijpqm.2021.118384 ◽

2021 ◽

Vol 34 (2) ◽

pp. 266

Author(s):

Bahram Nabilou ◽

Hassan Khorsandi ◽

Ali Reza Chavshin ◽

Aram Feizi ◽

Hasan Yusefzadeh

Keyword(s):

Productivity Analysis ◽

Medical Sciences ◽

Research Fields

Download Full-text

Drag Coefficients of Vertically-Mounted Full-Scale Blue Mussel Dropper Lines

Volume 7A: Ocean Engineering ◽

10.1115/omae2018-78534 ◽

2018 ◽

Author(s):

Arndt Hildebrandt ◽

Jannis Landmann ◽

Thorsten Ongsiek ◽

Nils Goseberg

Keyword(s):

Large Scale ◽

Blue Mussel ◽

Offshore Structures ◽

Develop Model ◽

Complex Structures ◽

Marine Aquaculture ◽

Drag Coefficients ◽

Blue Mussels ◽

Three Samples ◽

Physical Testing

Developments in marine aquaculture in the last 30 years indicate that the bivalve-related industry is feasible offshore and that opportunities for large-scale, industrious production of shellfish stock exists. The objective of the project “CAWX1607” is to develop, model and test such systems. However, the forces acting on suspension cultures, the most likely form of marine farm systems are unknown. Here, drag coefficients provide an efficient approach for the calculation of arbitrary complex structures by using the Morison equation. The CD-coefficients take into account vortex shedding effects as well as the surface roughness of the structure. This paper reports on developed and conducted tests at the medium wave and towing tank “Schneiderberg” (WKS) at the Ludwig-Franzius-Institute for Hydraulic, Estuarine and Coastal Engineering of the Leibniz University Hanover, Germany. The tests were conducted for current velocities between 0.25–1.0 m/s for three samples of blue-lipped mussel specimens. During physical testing the forces and moments in x-, y- and z-direction, the elevation of the water surface, a velocity profile in the vicinity of the live-blue mussels, as well as the velocities of the towing carriage were recorded. The developed methodology, data treatment as well as the resulting CD-coefficients are presented. Further, the CD-coefficients obtained are presented in the context of natural variation of living structures and discussed in comparison to CD—curve characteristics of offshore structures, e.g. rough cylinders.

Download Full-text

Progressive Collapse Approach Compared to the Traditional Temperature Screening on Structural Assessment of Offshore Structures Against Fire

Volume 3: Structures, Safety and Reliability ◽

10.1115/omae2016-54923 ◽

2016 ◽

Author(s):

Paula T. Nascimento ◽

Marco A. P. Rosas ◽

Leonardo Brandão ◽

Fernando Castanheira

Keyword(s):

Traditional Approach ◽

Progressive Collapse ◽

Screening Method ◽

Substantial Reduction ◽

Cost Savings ◽

Offshore Structures ◽

Significant Cost ◽

Fire Scenarios

The present study compares the progressive collapse approach with the traditional temperature screening method on determination of PFP requirements at topside offshore structures. The advantage to evaluate the consequences of fire scenarios on the global integrity and stability of topside modules can be revealed by a substantial reduction of the required amount of PFP, and consequently significant cost savings for operators, when compared to the traditional approach. In the case study presented in this paper, there is a reduction of 79% in PFP allocation.

Download Full-text

Spatial Stochastic Modeling of Adolescent and Under-Five Children Nutritional Status: A Case Study from Aceh, Sumatera Island, Indonesia

Proceedings of MICoMS 2017 - Emerald Reach Proceedings Series ◽

10.1108/978-1-78756-793-1-00090 ◽

2018 ◽

pp. 273-281

Author(s):

Siti Rusdiana ◽

Zurnila Marli Kesuma ◽

Latifah Rahayu ◽

Edy Fradinata

Keyword(s):

Nutritional Status ◽

Stochastic Modeling ◽

Under Five ◽

Under Five Children

Download Full-text

Structural Assessment of the Hull Response of an FPSO Unit to Dropped Objects: A Case Study

Polish Maritime Research ◽

10.2478/pomr-2019-0064 ◽

2019 ◽

Vol 26 (4) ◽

pp. 39-46 ◽

Cited By ~ 1

Author(s):

Ozgur Ozguc

Keyword(s):

Structural Damage ◽

Local Buckling ◽

Structural Response ◽

Offshore Structures ◽

Mechanical Equipment ◽

Structural Members ◽

Impact Area ◽

Explicit Dynamic ◽

The Impact

Abstract Offshore structures are exposed to the risk of damage caused by various types of extreme and accidental events, such as fire, explosion, collision, and dropped objects. These events cause structural damage in the impact area, including yielding of materials, local buckling, and in some cases local failure and penetration. The structural response of an FPSO hull subjected to events involving dropped objects is investigated in this study, and non-linear finite element analyses are carried out using an explicit dynamic code written LS-DYNA software. The scenarios involving dropped objects are based on the impact from the fall of a container and rigid mechanical equipment. Impact analyses of the dropped objects demonstrated that even though some structural members were permanently deformed by drop loads, no failure took place in accordance with the plastic strain criteria, as per NORSOK standards. The findings and insights derived from the present study may be informative in the safe design of floating offshore structures.

Download Full-text

Introduction to the marine biology case study (seminar session)

ACM SIGCSE Bulletin ◽

10.1145/331795.331910 ◽

2000 ◽

Vol 32 (1) ◽

pp. 427

Author(s):

Alyce Brady ◽

Michael J. Clancy ◽

Kathleen Larson

Keyword(s):

Marine Biology

Download Full-text

Stochastic Modeling of Chemical Compounds in a Limestone Deposit by Unlocking the Complexity in Bivariate Relationships

Minerals ◽

10.3390/min9110683 ◽

2019 ◽

Vol 9 (11) ◽

pp. 683 ◽

Cited By ~ 3

Author(s):

Battalgazy ◽

Madani

Keyword(s):

Mineral Resource ◽

Linear Model ◽

Stochastic Modeling ◽

Cross Correlation ◽

Projection Pursuit ◽

Chemical Compounds ◽

Spatial Dependency ◽

Mean Variance ◽

Mineral Resource Evaluation

Modeling multivariate variables with complexity in a cross-correlation structure is always applicable to mineral resource evaluation and exploration in multi-element deposits. However, the geostatistical algorithm for such modeling is usually challenging. In this respect, projection pursuit multivariate transform (PPMT), which can successfully handle the complexity of interest in bivariate relationships, may be particularly useful. This work presents an algorithm for combining projection pursuit multivariate transform (PPMT) with a conventional (co)-simulation technique where spatial dependency among variables can be defined by a linear model of co-regionalization (LMC). This algorithm is examined by one real case study in a limestone deposit in the south of Kazakhstan, in which four chemical compounds (CaO, Al2O3, Fe2O3, and SiO2) with complexity in bivariate relationships are analyzed and 100 realizations are produced for each variable. To show the effectiveness of the proposed algorithm, the outputs (realizations) are statistically examined and the results show that this methodology is legitimate for reproduction of original mean, variance, and complex cross-correlation among the variables and can be employed for further processes. Then, the applicability of the concept is demonstrated on a workflow to classify this limestone deposit as measured, indicated, or inferred based on Joint Ore Reserves Committee (JORC) code. The categorization is carried out based on two zone definitions, geological, and mining units.

Download Full-text