Susumu Fujii

Game theoretic enterprise management in industrial collaborative networks with multi-agent systems

Nowadays, virtual enterprise (VE) is an important paradigm of business management in an agile environment. VE exists in several kinds of business organization through multi-layered product flows. It is obvious that a mechanism, through which these different enterprises can be integrated together, is required for the better management of VE. In this paper, we focus on the negotiation process in VE formulation as a basic research to clarify its effective management. Each enterprise in VE is defined as a software agent with multi-utilities, and three types of primitive business models are targeted, such as the vertically integrated business model, horizontally specialized business model and hybrid business model. We develop a three-layered VE model for computer simulation so as to clarify VE formulation dynamism with the proposed negotiation mechanism.

Method for Target Tracking in Focused Ultrasound Surgery of Liver using Magnetic Resonance Filtered Venography

The purpose of this work is to develop a magnetic resonance (MR) technique for guiding a focal point created in focused ultrasound surgery (FUS) onto a specific target position in an abdominal organ, such as the liver, which moves and deforms with respiratory motion. The translational distance, rotational angles, and amount of expansion and contraction of the organ tissue were measured by obtaining the gravity points of the veins filtered from the sagittal, cine MR images of healthy livers during free breathing. Using the locations of the vessels at each time point, the target position at which the ultrasound focus was to be placed was estimated. In the volunteer experiments (N = 2), the lower limit of the spatial matrix dimension for delineating the veins was 128 x 128. The average displacement of the liver was 19.6 + 3.6 mm in superior-inferior (SI) direction and 3.1 + 1.4 mm in anterior-posterior (AP) direction. The deformations were 3.7 + 1.1 mm in SI direction and 3.0 + 1.2 mm in AP direction. The error between the actual and the estimated target point was 0.7 plusmn 0.5 mm in SI direction, 0.6 plusmn 0.4 mm in AP direction and 1.0 plusmn 0.5 mm in distance, and less than 2.1 mm in all the trials. These results suggested that the proposed technique is sufficient for targeting the focus on a specific tissue location and for tracking the slice slab for thermometry to cover the region of focus.

Machine Tool Automation

Numerical control (NC) is the greatest innovation in the achievement of machine tool automation in manufacturing. In this chapter, first a history of the development up to the advent of NC machine tools is briefly reviewed (Sect. 48.1). Then the machining centers and the turning centers are described with their key modules and integration into flexible manufacturing systems (FMS) and flexible manufacturing cells (FMC) in Sect. 48.2. NC part programming is described from manual programming to the computer-aided manufacturing (CAM) system in Sect. 48.3. In Sect. 48.4 and Sect. 48.5, following the technical innovations in the advanced hardware and software systems of NC machine tools, future control systems for intelligent CNC machine tools are presented.

A Basic Study on a Highly Distributed Simulation of Manufacturing Systems Under the Ubiquitous Environment

This study reports a new simulation paradigm devised to simulate manufacturing systems in its real operational stage. The objective manufacturing system is supposed to be under ubiquitous environment; in other words, all machines and equipments constituting a real manufacturing system are all equipped with intelligent devices and are connected to an information network. In the framework of the proposed simulation method, the simulation model is not built on one computer as is done in the conventional simulation, but is built on the network by integrating the intelligent devices. Each devise with properly embedded simulation functions plays as a simulation agent representing a resource or an entity in the conventional simulation model. This paper discusses the simulation functions required to each device to form a discrete event simulation system. The time management of the simulation and the event processes in the new simulation paradigm are described.Copyright

A study on automated scheduling methodology for machining job shop

In this study, scheduling method using a combination of auction-type real-time scheduling and simulation is proposed in order to automate the scheduling for machining job shop. The control mechanism which is essential for executing real-time scheduling and simulation simultaneously has been developed and implemented. The auction algorithm for the real-time scheduling which improves the delay of delivery date and amount of setup time at the same time is investigated. Also the method of simulation during the real-time scheduling which can predict the changing situation of the shop and automatically take countermeasures by adjusting the scheduling precondition is discussed. It is clarified that the proposed system has the ability to automate machining job shop scheduling.

Evaluation of a vessel‐tracking‐based technique for dynamic targeting in human liver

The purpose of this study was to evaluate a novel vessel‐tracking‐based technique for tracking of human liver. The novelty of the proposed technique is that it measures the translation and deformation of a local tissue region based on the displacements of a set of vessels of interest instead of the entire organ. The position of the target point was estimated from the relative positions of the center‐of‐masses of the vessels, assuming that the topological relationship between the target point and center‐of‐masses is unchanged during breathing. To reduce inaccuracy due to the delay between vessel image acquisition and sonication, the near‐future target position was predicted based on the vessel displacements in the images extracted from an image library acquired before the tracking stage. Experiments on healthy volunteers demonstrated that regardless of the respiratory condition, appropriate combinations of three center‐of‐masses from the vessels situated around the target‐tissue position yielded an estimation error of less than 2 mm, which was significantly smaller than that obtained when using a single center‐of‐mass trio. The effect of the tracking delay was successfully compensated, with a prediction error of less than 3 mm, by using over four images selected from the image library. Magn Reson Med, 2011.

Basic analysis on cell manufacturing scheduling method with combinatorial auction Integration of local search into auction mechanism

Cell manufacturing systems are widely introduced to cope with the dynamically changing market demands. We propose a scheduling method with combinatorial auction for cell manufacturing systems. Combinatorial auction, that is one of the autonomous distributed scheduling methods, can effectively allocate multiple assets. In this paper, we aim to reduce the calculation time by effective method based on local search. We analyze the relationship between optimality and calculation time by comparing with combinatorial auction that searches optimal solution.

A Study on Multi-Agent based Resource Allocation Mechanism for Automated Enterprise Contracting

A study on multi-agent based resource allocation mechanism for automated enterprise contracting. In this study we focus on automated contracting among enterprise negotiations with unbounded self-interested agents based on economic theory. Each enterprise is modelled as agent, and we consider agent-mediated Pareto optimal allocation of resources through market mechanism. We formulate virtual market model as a discrete resource allocation problem in dynamic situations, and demonstrate the applicability of the market concept with multi-agent paradigm to this framework. In this paper we clarify the proposed mechanism successfully calculates Pareto optimal solutions for the resource allocation in the agent contracting by comparing our method with conventional analytic approaches. Additionally we apply the mechanism into dynamic market environment, and analyse the rationality of the emerged market by computer simulation

A Basic Study on the Installation of Distributed Autonomous Production Scheduling System in Ubiquitous Environment

This paper considers an auction-based scheduling system in a job shop equipped with ubiquitous network environment to cope with dynamically changing market demands. Under such environment all machines and jobs are assumed to have computing and communication devices and can serve as intelligent agents. The functions for an auctioneer and for a participant are investigated to install the scheduling system as a distributed multi-agent system. The systems sending and receiving messages for the auction form a distributed system on a network, enabling an autonomous scheduling.

Interactive Determination of Irradiate Condition for External Beam Radiotherapy Treatment by Satisficing Trade-off Method

In the external beam radiotherapy, it is required to optimize the number of beams, the beam angles, and the strength of irradiation, which deliver the lethal dose to the tumor while limiting the dose absorbed in the normal tissue with fewer beams. In this study, we formulate this problem as a multiobjective linear programming, and propose a planning method to balance the dose distribution and the number of beams by using satisficing trade-off method. An aspiration level to each concerning point specifies the planners direction for each objective. Therefore, we applied cluster analysis to classify the objective functions, enabling the planner to set up aspiration levels for clusters rather than each objective, which significantly ease the planning task. An illustrated plan of a treatment for cerebral tumor is given to demonstrate the effectiveness of the proposed method.