Taioun Kim

Block assembly planning in shipbuilding using case-based reasoning

Abstract A process planning system using case-based reasoning (CBR) is developed for block assembly in shipbuilding. A block assembly planning problem is modeled as a constraint satisfaction problem where the precedence relations between operations are considered constraints. In order to find similar cases, we propose two similarity coefficients for finding similar cases and for finding similar relations. Due to the limited number of operation types, the process planning system first matches the parts of the problem and those of the case-based on their roles in the assembly, and then it matches the relations related to the matched part–pairs. The parts involved in more operations are considered first. The process planning system is applied to simple examples for verification and comparison. An interface system is also developed for extracting information from CAD model, for preparing data for process planning, and for visually verifying the assembly sequence.

Inducing inference rules for the classification of bovine mastitis

Mastitis, an inflammation within the mammary gland, can be a challenge to diagnose, based on dairy production records and on-farm observations, by the novice in the absence of culture results. The objective of this research was to establish a set of inference rules to classify bacterial causes of mastitis in dairy herds. Inductive inference utilizes specific observations about objects and an initial inductive hypothesis to obtain an inductive assertion that accounts for the observations. Interactive Dichotomizer 3 technology was used to create decision rules for classifying mastitis. It develops decision trees for discrete classification of data. The attributes adopted in this paper were lactation number, days in milk, persistency of milk production, number of severe cases, and average somatic cell count during the current lactation. The mastitis classification categories were divided into four logical groups based on common mastitis control schemes: no growth, contagious, environmental, and others. Causative organisms were determined by bacteriologic culturing of milk samples collected from 30 herds studied in the US. A total of 1253 sample records were selected to generate and test the rules. The established rules were tested using a randomly selected groups of 50 and 250 cows. The accuracy of mastitis classification using induced rules as compared with actual culture results ranged from 58 to 61%. The induced rules showed good potential for presumptive classification of mastitis based on production records. These diagnostic rules are easily implemented, lend themselves to computer analysis, and are easily understood by field practitioners and producers.

Structure modeling of machine tools and internet-based implementation

Reconfigurability of machine tools is one of the critical factors to realize the responsive manufacturing systems to satisfy the mass-customization production. This paper presents the methods to model and simulate the machine tools on Internet in response to change in the machining requirements. Specifically, a set of module combination rules and a modeling method of the structure of machine tools using connectivity graph are developed. In response to the user requirements, kinematic relations and structures of machine tools can be derived using the module combination rules and connectivity graph relationships. Internet-based simulator of machine tools is implemented and presented. The developed machine tool simulator can be used to verify the structure of machine tools derived from the user requirements

Integrated design of workcells and unidirectional flowpath layout

In manufacturing cells layout design with a unidirectional flow system, the accurate distance between two workcells can be uncovered with both the determination of IO port locations after the layout design of the cell with its orientation and the unidirectional flowpath layout design. This paper presents the method to obtain a global solution for manufacturing workcells and unidirectional flowpath layout design (ICFLD) with consideration of IO ports of workcells. The flow distance between two workcells is calculated from output port of one workcell to input port of the other workcell through the unidirectional flowpath layout. A zero-one integer programming model is developed for the ICFLD problem. And a heuristic algorithm for the ICFLD problem is developed by decomposing the ICFLD problem into two subproblems and iteratively and alternately solving the decomposed subproblems. Computational experiments are performed and its results are analyzed.

Analytic Network Process for analysing Supply Chain relationship

The criteria related to the Supply Chain (SC) performance are interrelated with each other. In analysing the performance of SC relationship and interdependence, Analytic Network Process (ANP) can be well suited. ANP, is a systematic approach that can deal with both hierarchical criteria and their dependencies. In this paper, a framework of SC performance is proposed based on ANP. Multicriteria decision structures are constructed with hierarchy and dependency. A supermatrix is defined and solved following the proposed steps. ANP-based model is applied for decision making in prioritising the alternatives for the improvement of SC performance.

Adapting genetic algorithm and tabu search approaches for unidirectional AGV flowpath design problems

In this paper we suggest an evolutionary computational approach by applying a combination of a genetic algorithm and a tabu search to obtain a good solution for relatively large unidirectional automated guided vehicle flowpath design problems. Unidirectional flowpaths are used to lessen the traffic control loads for large fleets of vehicles and to increase the efficiency in use of space. The flow path design is one of the most important steps in efficient vehicle systems design. We use an genetic algorithm to obtain partially directed networks, which are then completed and afterwards improved by a tabu search. A set of computational experiments is conducted to show the efficiency of the proposed solution procedure and the results are reported.

Web-Based Distributed Multi-Agent Architecture for Implementing Value Nets

The value net creates a network of suppliers, and distributors such that the product becomes customer centric. In order to implement the value net model, information processing and distribution need to occur in real time. Software agent technology is becoming popular due to the inherent characteristics of autonomy, distributedness and modularity. In this reserach, we adopt agent technology to handle all real time decision processes, making the value net model a complex multi-agent network of decision makers. For the agents to properly coordinate their respective activities we develop Valcomm, a Web-based multi-agent language grounded in the XML and Java. Such a system will enhance the overall performance of all the participating organizations. Valcomm will truly implement extended enterprises.

Product family design based on analytic network process

In order to remain productive and efficient in todays global competition, mass customization is adopted in many leading companies. Mass customization through product family and product platform enables global enterprise to develop new products with flexibility, efficiency and quick responsiveness. Thus, product family is well suited to satisfy the mass customization. Product family is defined as a group of related products that share common features, components, and subsystems; and satisfy a variety of market niches. The purpose of this paper is to propose a product family design architecture that satisfies customer requirements with minimal efforts. The decision making process for a new product development requires a multiple criteria decision making technique with feedback. An analytical network process (ANP) is adopted for this purpose. An example product is chosen and product family is derived based on the proposed architecture