Moonsoo Shin

Manufacturing enterprise collaboration based on a goal-oriented fuzzy trust evaluation model in a virtual enterprise

To cope with the rapidly changing manufacturing environment, enterprise collaboration is getting increasingly more attention than ever before. The virtual enterprise (VE) is a concept that supports temporary alliances of manufacturing enterprises that have various collaboration models, such as extended enterprise, networked enterprise, concurrent enterprise, etc. Selection of trustworthy partners and trust building are important in virtual domains because they have largely been affecting the success of a VE. However, because of its complexity of trust, trust models in the literature are limited in their ability to cope with dynamic and virtual environment. In this paper, we propose a trust evaluation method of supporting enterprise collaboration and maximizing the satisfaction of cooperation. In this context, trust means the goal achievement probability. Trust value of an enterprise can be obtained by a fuzzy inference system whose rule-base is based on the top-level goal of a VE. According to the selectors preference, various rules can be applied to trust evaluation. For further study, the planning and scheduling problems should be considered along with the trust-based partner selection for collaboration among manufacturing enterprises.

Self-evolution framework of manufacturing systems based on fractal organization

The turbulent environment of modern times breeds a need to ensure flexibility and responsiveness for manufacturing systems. The conventional manufacturing systems, however, are not suitable for the dynamic environment because of their rigid structure. Thus, it is necessary to establish a novel manufacturing system which is capable of proactively perceiving the environment and of autonomously adapting to the changing environments. The purpose of this paper is to propose a self-evolution framework of manufacturing systems that facilitates continuous and quick adaptation. In a self-evolutionary manufacturing system, each production resource regulates its own goal, responding to the changes in its environment. Moreover, the organizational structure of the production resources is also dynamically transformed into a form suitable to the changed goal and the emerging environment. Especially, the proposed framework adopts fractal organization for its principal control architecture.

MANPro: mobile agent-based negotiation process for distributed intelligent manufacturing

This paper examines negotiation procedures in an agent-based distributed shop floor control system (SFCS). A distributed SFCS is under a heterogeneous environment, which is controlled through negotiations between autonomous agents. The negotiation-based control can be considered as the core of a distributed control paradigm. An efficient information exchanging mechanism and an information model with reasonable structure are indispensable for effective negotiations. This paper proposes a novel negotiation mechanism, called a mobile agent-based negotiation process (MANPro), which applies a mobile agent system to the process of information exchange. Since using mobile agents allows each component to execute asynchronously and autonomously and to adapt dynamically to the execution environment, MANPro may guarantee autonomy of agents. Moreover, it is possible to build a fully distributed and autonomous SFCS by using MANPro. MANPro is based on the agent-based control architecture, which includes a communication architecture and an information architecture. The communication architecture provides the exchanging mechanism of information, defining functional modules to support the mechanism while the information architecture provides the framework for information modelling on negotiation, proposing information models required for introducing the ontology concept.

Conflict detection and resolution for goal formation in the fractal manufacturing system

The fractal manufacturing system (FrMS) is based on the concept of autonomously cooperating agents referred to as fractals. A fractal is a set of self-similar agents whose goal can be achieved through cooperation, coordination, and negotiation among the agents for themselves. A fractal has fractal-specific characteristics (e.g. self-similarity, self-organization, self-optimization, goal-orientation, and dynamics), and it also has the characteristics of an agent (e.g. autonomy, mobility, intelligence, cooperation, and adaptability) at the same time. In the FrMS, a goal can be regarded as the status which the system aspires to be in. The goal-formation process (GFP) in the FrMS is a process of generating goals and modifying them by coordination between agents. In the GFP, conflicts may occur between goals, which can drive a system to become inefficient. In this paper, a conflict resolution mechanism via agent-based negotiation is proposed for facilitating the GFP. The scheme deals with non-fixed goals. The mobile agent-based negotiation process (MANPro), in which a mobile agent is used for information-exchanging and problem-solving, is used for negotiations in this scheme. The proposed mechanism is illustrated with a goal formation scenario in an exemplary FrMS.

A goal-oriented trust model for virtual organization creation

Virtual organization (VO) is a main organizational paradigm for enterprises to collaborate in the rapidly changing environment. Advances in information and communication technologies are accelerating collaboration among enterprises in different domains as well as unknown enterprises. In this environment, an enterprise faces more chances to cooperate with other enterprises through the internet. Trust is a key concept in many kinds of interactions, allowing an enterprise to act under uncertainty and with the risk of negative consequences. To minimize the operating risk and guarantee the success of a VO, trust evaluation of potential partners should be considered during the partner selection process. However, trust evaluation methods in the literature have limitations in applying them to small and medium enterprises because they are based on evaluation of human experts. In this paper, a goal-oriented trust model is proposed to evaluate the trust values of enterprises. In the context, trust is the probability that a trustee satisfies the goals when it completes assigned tasks. This paper introduces the concept of a goal-oriented trust model with the core constructs of a goal, a project, a task, and a capability. It further addresses an example of applying the proposed model to the partner selection process of a project-based VO creation.

Reinforcement learning approach to goal-regulation in a self-evolutionary manufacturing system

Highlights? We propose a goal-regulation mechanism that applies a reinforcement learning approach to autonomous goal-formation. ? Individual goals are regulated by a neural network-based fuzzy inference system called goal-regulation network (GRN). ? The GRN is updated by a reinforcement signal from another neural network called goal-evaluation network (GEN). ? The GEN approximates the compatibility of goals with current environmental situation. ? The proposed mechanism is validated by a simulation study on a production planning problem. Up-to-date market dynamics has been forcing manufacturing systems to adapt quickly and continuously to the ever-changing environment. Self-evolution of manufacturing systems means a continuous process of adapting to the environment on the basis of autonomous goal-formation and goal-oriented dynamic organization. This paper proposes a goal-regulation mechanism that applies a reinforcement learning approach, which is a principal working mechanism for autonomous goal-formation. Individual goals are regulated by a neural network-based fuzzy inference system, namely, a goal-regulation network (GRN) updated by a reinforcement signal from another neural network called goal-evaluation network (GEN). The GEN approximates the compatibility of goals with current environmental situation. In this paper, a production planning problem is also examined by a simulation study in order to validate the proposed goal regulation mechanism.

Temporal and spatial characterization of harmonics structures of relativistic nonlinear Thomson scattering.

The harmonics of the scattering of a femtosecond intense laser pulse by an electron has been numerically investigated. The harmonic spectrum shows interesting red shifts and parasitic lines in the blue sides of harmonic lines. The red shift of the lines is found to be caused by the dilation of laser oscillation experienced by an electron due to its relativistic drift motion along the direction of a driving laser propagation and the parasitic lines come from the variation of the laser intensity. The angular distribution of each higher harmonic line shows double peak patterns in the forward direction. The backward scattering has its own distinct pattern: line-shaped nodes perpendicular to the laser electric field, the number of which is the harmonic order number minus one. As the harmonic order increases, the primary peaks of higher harmonics move from the backward to the forward direction of the laser propagation. In the time domain, each radiation pulse in the case of a linearly-polarized laser pulse has a double peak structure due to the disappearance of the acceleration during the half cycle of an electrons oscillation.

r-FrMS: a relation-driven fractal organisation for distributed manufacturing systems

Up-to-date market dynamics and decentralisation have brought about the need of flexible and robust organisational structures for manufacturing resources. To meet the need of such an environment, the manufacturing system should be equipped with an open, reconfigurable and scalable organisational structure. This paper proposes a novel organisational model, referred to as a relation-driven fractal organisation, to meet the requirements. The proposed model applies the concept of a fractal to its organisational structure and adopts a relational pattern between composing entities as a basic building block for organising. In this paper, the existing fractal-like systems involved in manufacturing systems are investigated, and the fractal organisation is derived as their super-ordinate concept. Then, r-FrMS, a relation-driven fractal organisation applied into distributed manufacturing systems, is proposed along with its organising mechanism which adopts employment relations between manufacturing resources as its organising principle.

Bid generation and evaluation for MANPro-based real time scheduling

This paper proposes a bid generation and evaluation scheme and an information model for real-time scheduling. It is well known that an agent-based control approach performs according to both the negotiation mechanism itself and the single agent internal strategic policies. Mobile agent-based negotiation process (MANPro), which has been proposed in our previous work, concerns the first issue of the negotiation mechanism. This paper concerns the second issue of the single agent internal strategic policies. It explains how bids are generated and evaluated and how agents obtain mutual agreement in MANPro. First, the generic bid generation and evaluation framework for MANPro-based negotiation is proposed. Then, the generic framework is applied to a real-time scheduling system for a distributed shop floor control system (SFCS).

Development of Green-BOM to Manage Eco-friendly Information on Products and Manufacturing Processes

The world has faced with various environmental problems such as climatic change, global pollution, and depletion of natural resources. Conventional economic development continues not only to intensify the magnitude of the problems but also to damage growth potential of future generations. Therefore, recent manufacturers are highly required to accommodate themselves to sustainable development that aims at preventing the loss to the future generations. Moreover, the manufacturers are under heavy pressure from various environmental regulations. This paper proposes green bill of material (Green-BOM) which conforms to the environmental regulations to restructure eco-friendly manufacturing system. Green-BOM is useful for managing green product and process information to satisfy several environmental regulations by recording energy consumption, recycle rate, volatile organic compounds (VOCs), substance information, and so on.