• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.352-366
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• 2021

To decrease Europe's harmful emissions, the European Union aims to substantially increase its offshore wind energy capacity. To further develop offshore wind energy, investment in ever-larger construction vessels is necessary. However, this market is characterised by seemingly unpredictable growth of market demand, turbine capacity and distance from shore. Currently it is difficult to deal with such market uncertainty within the ship design process. This research aims to develop a method that is able to deal with market uncertainty in early ship design by increasing knowledge when design freedom is still high. The method uses uncertainty modelling prior to the requirement definition stage by performing global research into the market, and during the concept design stage by iteratively co-evolving the vessel design and business case in parallel. The method consists of three parts; simulating an expected market from data, modelling multiple vessel designs, and an uncertainty model that evaluates the performance of the vessels in the market. The case study into offshore wind foundation installation vessels showed that the method can provide valuable insight into the effect of ship parameters like main dimensions, crane size and ship speed on the performance in an uncertain market. These results were used to create a value robust design, which is capable of handling uncertainty without changes to the vessel. The developed method thus provides a way to deal with market uncertainty in the early ship design process.

• Structural Engineering and Mechanics
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• v.84 no.5
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• pp.651-664
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• 2022

A precise prediction of the ultimate bond strength between rebar and surrounding concrete plays a major role in structural design, as it effects the load-carrying capacity and serviceability of a member significantly. In the present study, Gaussian models are employed for modelling bond strength of ribbed steel bars embedded in concrete. Gaussian models offer a non-parametric method based on Bayesian framework which is powerful, versatile, robust and accurate. Five different Gaussian models are explored in this paper-Gaussian Process (GP), Variational Heteroscedastic Gaussian Process (VHGP), Warped Gaussian Process (WGP), Sparse Spectrum Gaussian Process (SSGP), and Twin Gaussian Process (TGP). The effectiveness of the models is also evaluated in comparison to the numerous design formulae provided by the codes. The predictions from the Gaussian models are found to be closer to the experiments than those predicted using the design equations provided in various codes. The sensitivity of the models to various parameters, input feature space and sampling is also presented. It is found that GP, VHGP and SSGP are effective in prediction of the bond strength. For large data set, GP, VHGP, WGP and TGP can be computationally expensive. In such cases, SSGP can be utilized.

• Archives of design research
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• v.17 no.3
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• pp.421-430
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• 2004

The aim of this research is to develop communication model and tools that would help in incorporating user experience into information appliance product development. To do so, this research suggested three major modelling techniques, including user-experience model, design strategy model and experience product model. Using these modelling tools, any members in design teams (investigator and designers) will be able to communicate their own ideas and research results each other at any period of the product development process. Each tools have distinct factors that would help identify elements in the user research stages, idea generation stages and product development stages. To verify the efficiency of these models, the case study was conducted with final year students at their studio class. As a result, the benefit of using these tools were identified as 1) these tools accelerate the communication between user researchers, designers and engineers and 2) evaluation process of the product is much more dearer that before. and 3) various user research techniques can be explored.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.441-444
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• 1988

This paper presents a methodology for developing the graphic simulator for a robotic workcell. The Petri Net model is applied to described the system state and the workcell simulation is performed by the event scheduling approach of the model. For the graphic display of simulation process, the information of the workcell resources are stored in hierachically-structured data_babe, and the geometry of the resources is described by robot modelling, component modelling, and world modelling.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.4
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• pp.414-427
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• 1990

This paper presents the development of the graphic simulator for an assembly workcell. The assembly workcell consists of two PUMA 560 manipulators, a conveyor belt system, a work table, and a vision sensor. In this study, the Petri Net theory is applied to model the assembly workcell and to construct the simulator. The event scheduling approach is used to simulate the cell. In order to show the graphic display of the simulation process, robot modelling, component modelling, and world modelling are included. The developed simulator is used to display the transition of the system state during the simulation. It is also used as a tool in selection the best resource states by studying the performance of the system as the resource states are changed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.720-725
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• 1997

This paper is to study the wind effect of the large scale gantry crane. It is used to control the sway of gantry crane in the loadingiunloading job of containers. I'hls is very important in the automated container terminal because the sway of handling equipments in pard is caused by thc l~nexpected disturbance such as wind and dynamic inertia by deriving force. This study shows the process of the modelling simulation of the wind effect of the sway motion of the gantry crane. Pro-Engineer, ANSYS and DAD'; ~ rr . used for 3D solid modelling and dynamic simulation. Though this study did not use the real parameters. the ; cwl ~ shows the trend of the wind effect is very large in the large scale crane and should be considered in design of the large scale gantry crane. In future, if the study is done by using the real parameters, the result is much more ~ise!'ul for dynamic control and design of gantry crane.

• Journal of The Korean Digital Architecture Interior Association
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• v.6 no.2
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• pp.17-23
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• 2006

The purpose of this study was to investigate how student felt the strengths and shortness of presentation methods for formation of interior spaces. For this study, the process of the interior architecture design class was divided into three stages: the programming. the design development, and the design completion. In the design development stage, students used presentation methods: hand sketch, scale model, computer modeling, and virtual realty. The strengths of hand sketch was that quick expression. Models provided three-dimensional feelings. Computer modelling provide realistic color and texture. Virtual reality provided three-dimensional immersion and real scale. It is effective that students collect brain storm images using quick hand sketch in the beginning of design development stage. After that, they compose interior spaces in study models with small scale. Watching the models, they design details of spaces by using hand sketch and computer modelling. Using virtual reality, they can check the scale and circulation. Finally, they complete computer modelling by texture mapping and check the final design in virtual reality.

• Journal of The Korean Digital Architecture Interior Association
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• v.6 no.2
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• pp.25-30
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• 2006

The purpose of this study was to investigate how student felt the strengths and shortness of presentation methods for formation of interior spaces. For this study, the process of the interior architecture design class was divided into three stages: the programming. the design development, and the design completion. In the design development stage, students used presentation methods: hand sketch, scale model, computer modeling, and virtual realty. The strengths of hand sketch was that quick expression. Models provided three-dimensional feelings. Computer modelling provide realistic color and texture. Virtual reality provided three-dimensional immersion and real scale. It is effective that students collect brain storm images using quick hand sketch in the beginning of design development stage. After that, they compose interior spaces in study models with small scale. Watching the models, they design details of spaces by using hand sketch and computer modelling. Using virtual reality, they can check the scale and circulation. Finally, they complete computer modelling by texture mapping and check the final design in virtual reality.

• Structural Engineering and Mechanics
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• v.15 no.4
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• pp.477-493
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• 2003

Masonry is not a simple material, the influence of mortar joints as a plane of weakness is a significant feature and this makes the numerical modelling of masonry very difficult especially when dynamic (seismic) analysis is involved. In order to develop a simple numerical model for masonry under earthquake load, an analytical model based on Distinct Element Method (DEM) is being developed. At the first stage, the model is applied to simulate the in-plane shear behaviour of an unreinforced masonry wall with and without opening where the testing results are available for comparison. In DEM, a solid is represented as an assembly of discrete blocks. Joints are modelled as interface between distinct bodies. It is a dynamic process and specially designed to model the behaviour of discontinuities. The numerical solutions obtained from the distinct element analysis are validated by comparing the results with those obtained from existing experiments and finite element modelling.

• Journal of Environmental Impact Assessment
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• v.13 no.4
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• pp.213-222
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• 2004

Exergy is defined as the amount of work (entropy-free energy) a system can perform when it is brought into thermodynamic equilibrium with its environment. Exergy measures the distance from the inorganic soup in energy terms. Therefore, exergy can be considered as fuel for any system that converts energy and matter in a metabolic process. The aim of this study is to introduce structural dynamic modelling which is based on maximum exergy principle. Especially, almost ecological models couldn't explain algal succession until now. New model (structural dynamic model) is anticipated to predict or explain the succession theory. If the new concept using maximum exergy principle is used, algal succession can be explained in many actual cases. Therefore, It is estimated that structural dynamic model using maximum exergy principle might be a excellent tool to understand succession of nature from now on.