A Network Science Approach to Understanding and Generating Ship Arrangements in Early-Stage Design.

In recent years, automated approaches for creating ship general arrangements in early-stage design have been developed. These approaches seek to avoid “black box” implementations by keeping the designer involved in the layout generation and selection process, but they do not avoid it entirely. Existing methods first generate layouts, next evaluate each layout’s quality, and subsequently filter out poor designs in an iterative process. In addition, desires to move toward full distributed system layouts in early-stage design have only led to more highly-refined CAD-style implementations requiring extensive modeling and computation time. This dissertation asserts that there is a need to shift away from the current trajectory toward higher-fidelity three-dimensional layout models and re-vector toward a perspective that focuses on understanding and inherently respects the fundamental underlying relationships among elements within those models. The research offered in this thesis uses network science to envision the layout problem from a new perspective. In this view, design relationships are information inputs into layout-related analyses rather than only post-processors for evaluating layouts. This is consistent with existing design processes in which human designers attempt to keep relevant relationships in the back of their mind at all times to inform decisions. Network nodes represent ship compartments and edges correspond to design constraints forming a relationship network. First, network concepts of centrality and hierarchy are used to highlight and rank the embedded drivers of an early-stage arrangement prior to developing spatial layouts by directly analyzing the relationship network in a methodical and holistic manner. The obscured design intent of a notional WWII naval vessel is exposed using the hierarchical approach. Second, a network partitioning method is used to cluster shipboard elements into communities of mutually-compatible elements to minimize the degradation of other items located in the same region of the ship. These communities can form the basis of functional zone definitions. Varying the number of partitions reveals a multi-scale depiction of the relationship network. Third, the communities are assigned to structural zones based on cumulative zone preference values. Finally, two new visualization techniques help designers establish connections between the network of inter-element relationships and spatial ship arrangements.PHDNaval Architecture & Marine EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/96126/1/justinwg_1.pd

Concurrent optimization of process parameters and product design variables for near net shape manufacturing processes

This paper presents a new systematic approach to the optimization of both design and manufacturing variables across a multi-step production process. The approach assumes a generic manufacturing process in which an initial Near Net Shape (NNS) process is followed by a limited number of finishing operations. In this context the optimisation problem becomes a multi-variable problem in which the aim is to optimize by minimizing cost (or time) and improving technological performances (e.g. turning force). To enable such computation a methodology, named Conditional Design Optimization (CoDeO) is proposed which allows the modelling and simultaneous optimization of process parameters and product design (geometric variables), using single or multi-criteria optimization strategies. After investigation of CoDeO’s requirements, evolutionary algorithms, in particular Genetic Algorithms, are identified as the most suitable for overall NNS manufacturing chain optimization The CoDeO methodology is tested using an industrial case study that details a process chain composed of casting and machining processes. For the specific case study presented the optimized process resulted in cost savings of 22% (corresponding to equivalent machining time savings) and a 10% component weight reduction

Resource selection and route generation in discrete manufacturing environment

When put to various sources, the question of which sequence of operations and machines is best for producing a particular component will often receive a wide range of answers. When the factors of optimum cutting conditions, minimum time, minimum cost, and uniform equipment utilisation are added to the equation, the range of answers becomes even more extensive. Many of these answers will be 'correct', however only one can be the best or optimum solution. When a process planner chooses a route and the accompanying machining conditions for a job, he will often rely on his experience to make the choice. Clearly, a manual generation of routes does not take all the important considerations into account. The planner may not be aware of all the factors and routes available to him. A large workshop might have hundreds of possible routes, even if he did know it all', he will never be able to go through all the routes and calculate accurately which is the most suitable for each process - to do this, something faster is required. This thesis describes the design and implementation of an Intelligent Route Generator. The aim is to provide the planner with accurate calculations of all possible production routes m a factory. This will lead up to the selection of an optimum solution according to minimum cost and time. The ultimate goal will be the generation of fast decisions based on expert information. Background knowledge of machining processes and machine tools was initially required, followed by an identification of the role of the knowledge base and the database within the system. An expert system builder. Crystal, and a database software package, DBase III Plus, were chosen for the project. Recommendations for possible expansion of and improvements to the expert system have been suggested for future development

Fourth Conference on Artificial Intelligence for Space Applications

Proceedings of a conference held in Huntsville, Alabama, on November 15-16, 1988. The Fourth Conference on Artificial Intelligence for Space Applications brings together diverse technical and scientific work in order to help those who employ AI methods in space applications to identify common goals and to address issues of general interest in the AI community. Topics include the following: space applications of expert systems in fault diagnostics, in telemetry monitoring and data collection, in design and systems integration; and in planning and scheduling; knowledge representation, capture, verification, and management; robotics and vision; adaptive learning; and automatic programming

Modeling And Applying Biomimetic Metaheuristics To Product Life Cycle Engineering

Due to its potential for significant impact, interest continues to grow in the assessment of products from a life cycle perspective. As the nature of products shifts from mechanized and Newtonian to more adaptive and complex, the behavior of products more closely resembles biological organisms in community. The change in product nature is increasingly mirrored at the component level. The work presented in this dissertation is twofold. First, the research proposes a general, systematic and holistic classification of life cycle data to transform the design problem into an optimization problem. Second, the research proposes two new metaheuristics (bio-inspired and socio-inspired) to solve optimization problems to produce grouped solutions that are efficient, evolvable and sustainable. The bio-inspired approach is schooling genetic algorithms (SGA), while the socio-inspired approach is referred to as genetic social networks (GSN). SGA is an approach that combines fish schooling concepts with genetic algorithms (GAs) to enable a dynamic search process. The application of GA operators is subject to the perception of the immediate local environment by clusters of candidate solutions behaving as schools of fish. GSN is an approach that adds social network concepts to GAs, implementing single and dyadic social interactions of social groups (clusters of similar candidate solutions) with GA operators. SGA and GSN both use phenotypic representations of a hypothetical product or system as input. The representations are derived from the proposed life cycle engineering (LCE) data classification. The outputs of either method are the representations that are more than likely to perform better, longer, and more autonomously within their environment during their life cycle. Both methods can also be used as a decision making tool. Both approaches were tested on product design problems with differing parametric relations, underlying solution space, and problem size

Methods for Analyzing Early Stage Naval Distributed Systems Designs, Employing Simplex, Multislice, and Multiplex Networks.

Naval ships are some of the most complex systems ever engineered. The process by which they are designed is similarly complex. The complexity and disjointedness of this process leads to the creation of disparate and incomplete ship design information created by different systems of analysis, completed by different design groups, using different tools, at different levels of fidelity. Distributed system design decisions based off this disparate and incomplete information lead to unnecessary complexity when the design is transitioned from the early design stage to the detailed design stage. This dissertation presents novel network theory-based methods for better understanding and analyzing the implications of early stage distributed system design decisions. This new method introduces network theory concepts such as degree distribution, system interdependence, and community to the field of distributed systems design as metrics for determining system robustness, as well as develops new techniques for representing physical systems as networks. Additionally, a personnel movement modeling and analysis method, derived from the network concept of betweenness centrality, is developed. This dissertation documents the first use of multislice and multiplex structures in the analysis of physical systems. System design evolutions are analyzed using multislice network structures and the interactions between systems are investigated using multiplex network structures. These two structures are combined into a novel time-dependent multiplex network structure that is developed in this work. This new structure is used to track the evolution of systems interactions. A new network complexity metric based on the concepts of planarity and network communities is created for this research in a response to lack of methods for studying the planar and near planar networks that often arise in the study of real systems. The methods presented in this dissertation do not require complex 3D CAD models or simulations. Therefore, they can be used by a single naval architect to gain insight into the implications of design decisions in the early design stages. This will result in improved naval distributed systems designs that are easier to design, maintain, and upgrade.PhDNaval Architecture and Marine EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/108838/1/rigterin_1.pd

Management: A continuing bibliography with indexes

This biliography lists 919 reports, articles, and other documents introduced into the NASA scientific and technical information system in 1981

Aeronautical engineering: A continuing bibliography with indexes (supplement 249)

This bibliography lists 637 reports, articles, and other documents introduced into the NASA scientific and technical information system in November, 1988. Subject coverage includes: design, construction and testing of aircraft and aircraft engines; aircraft components, equipment and systems; ground support systems; and theoretical and applied aspects of aerodynamics and general fluid dynamics

SUPPORTING FUNCTIONALITY-BASED DESIGN IN COMPUTER-AIDED DESIGN SYSTEMS

Designs are conceptualized in terms of the functions they need to accomplish. The need for a new product design arises as a result of the identification of a new functionality to be accomplished by the product. That is, design is functionality driven. However, existing CAD tools are not equipped to capture functionality or reason in such a fashion to support design for product functionality. This research proposes a new design formalism to enable functionality-driven design of mechanically engineered products. This procedure provides a methodology that allows a designer to model product functionality and to carry out conceptual design with the aid of a computer. It also serves as a bridging tool between the conceptual design phase and detailed design phase of a product. Thus, the primary objective of this research is to develop a methodology that will support the following activities in CAD systems: functionality modeling, functionality data structuring, and form conceptualization.The functionality modeling methodology developed in this work includes the use of operands, operators, and coupling bonds to describe product functionality in CAD systems. The Universal Modeling Language (an object-oriented programming technique) is used to model product functionality in computer systems. The tools developed in this research provide a means of modeling and propagating product functionality information to downstream design activities. The propagation of functionality as a constraint is achieved using Extensible Markup Language (XML) data files. These tools also provide a mechanism for verifying and enforcing constraints on solid CAD models. The functionality definition interface is implemented with a customized Microsoft Visio graphics engine.The tools developed in this research provide a means of modeling and propagating product functionality information to downstream design activities. It also provides a mechanism for verifying and enforcing constraints on solid CAD models. The functionality definition interface is implemented with a customized Microsoft Visio graphics engine