Research And Application Of Game Theoretic Methodology In Naval Architecture & Ocean Engineering

Already we are in the information age, and the rapid developments of knowledge-based economy promote the human society's rapidly and profoundly changing. The behavior according to the traditional design method is no longer able to meet the requirements of modern design fully, and the design process has to accept the changes from traditional to modern.During the design process of the modern complex industrial product, as ship, there will be a large number of unavoidable multi-objective optimization problems. For conventional marine vessels the most commonly used method is so called "mother-type transformation", which has a certain limitation caused by inherent over-reliance on data collection of successful design paradigm of the past. In the filed of naval architecture and ocean engineering, the most popular used concept is the classic "design spiral". It is widely recongnized that the "design spiral" is useful to indicate the interactive nature of the design process, and the process of ship design is assumed to be cyclical, sequential and iterative but not open, parallel and collaborative.Game analysis ideas have been successful and widely used in many areas of scientific research. GAME THEORETIC METHODOLOGY can propose solutions that based on the idea and basic principles of game theory to solve engineering multi-objective optimization problems. By using GAME ANALYSIS MODEL to achieve the description and analysis of problems a new way of thinking and logic analysis process has been established while the open and systematic characteristics of this metod has beem reflected. For the defects of traditional methods and concept, a study of the application of some new design methodoloty has been carried out which starts from some of the basic design problems.Here we take the design of the ship cabin layout as an example, in a certain area of space to locate a number of furniture or equipment to enable the space as a living compartment with quite some design requirements. This issue can be abstracted as a multi-objective optimization problem. Each cabin indoor furniture/equipment has an optimal location of layout but in a limited space it is often led to geometry conflicts. In this article we propose two analytical solutions to address this issue. One is weighted sum method. Different weights offered to optimize objectives and have these objectives realized orderly with score assignment. Calculate the weighted sum of different objective portfolio and take combination with maximum value as the final optimization. The other is GAME THEORETIC ANALYSIS METHOD. Consider the characteristics of the problem, using game theory to describe the problem with a game model. The arrangement block-units which are established based on the single furniture/equipment are defined as players of the game. The choice of the location of each block-unit is defined as strategy. The function level of the block-unit is defined as payoff. By attaining the equilibrium of the game we get the final solution of a multi-objective optimization issue.Given the complex nature characteristics of ship preliminary design combined with multidisciplinary cooperation and multi-objective optimization theoretic analysis method can be applied into such design process to deal with the problems. The various discipline/subject design teams will be defined as players. The design objectives are defined as expected payoffs. When the game equilibrium is obtained, the players strategies under the interactive cooperate circumstance are guides for design teams in design process that most deserve our attention. Original application of MATRIX OF STRATEGIES is to decompose the complex game analysis model and simplify the solving process. At the same time, the idea of game analysis is also applied to the research of MDO (Multidisciplinary Design Optimization) algorithm design. With the introduction of a mechanism originated from game theory into the respective optimization process of individual subsystems a new multi-level algorithm of MDO created, through which the open parallel and collaborative pattern in a single cycle of ship design stage can be achieved.Offshore platforms just as ships belong to marine engineering equipments whose design processes are quite different from that of the ships. The design of a platform is lack of mature prototype product as "mother type", and it should start with the desired goals of various functional subsystems to constitute the final solution gradually. With the application of game theoretic analysis method to the design of some jack-up unit the design process was clearly described by matrix-like game theoretic model and the complex issues are effectively simplified with the help of sub-game decomposition. When the design constraints of every subsystem are clarified the design activities can be well planned and the final solutions will be in our reach.At last, a modified theoretic analysis method is proposed in light of the modular design and life-cycle design concept. The scope of application of theoretic analysis method is expanded to analyze some a jack-up unit's life cycle engineering activities. Draw on the concept of systematic criteria, a jack-up is modularized according to different service functionality and the game analysis model is to be built base on this module division. Also the model is described and analyzed through MATRIX OF STRATEGIES. Then time variable be put into the model to adapt to life-cycle concept, and every stage of the product life cycle with time factors is taken account in game model. The origin game analysis model turn into the REAL-TIME GAME ANALYSIS MODEL. Thus, game theoretic method will be suitable for all stage of the entire product life cycle engineering.